This document describes the structure and function of organelles in animal cells. It discusses the nucleus, cytoplasm, mitochondria, ribosomes, lysosomes, endoplasmic reticulum, Golgi apparatus, cytoskeleton including microtubules, microfilaments, intermediate filaments, centrosomes, peroxisomes, and plasma membrane. The key functions of these organelles include protein synthesis, aerobic respiration, intracellular digestion, lipid and protein transport and modification, cellular structure and movement, and cell division.
Clinical significance of carbohydrates presentation130144011
The document discusses carbohydrates of biological and clinical significance and glucose absorption. It covers classification of carbohydrates, their biological and clinical importance, digestion and absorption of glucose through sodium-glucose cotransporters, and important glucose transporters. The seminar objectives were to discuss carbohydrate structure and function, glucose homeostasis, dietary fiber significance, and digestion and absorption of carbohydrates. Key topics included biological roles of carbohydrates, clinical implications such as glycated hemoglobin, and the five phase mechanism of glucose homeostasis.
Metabolism of amino acids (general metabolism)Ashok Katta
Metabolism of amino acids (general metabolism).
Part - I of amino acid metabolism.
This presentation covers Transamination, deamination, formation and Transport of Ammoniaand etc.
Unit 7 : Carbohydrates metabolism & disordersDrElhamSharif
This document provides an overview of carbohydrate metabolism and disorders by Dr. Elham Sharif. It covers objectives, carbohydrate classification and functions, glucose metabolism pathways, hormonal control of glucose levels, normal blood glucose and urine glucose levels, hormones that affect blood glucose, abnormalities in carbohydrate metabolism including lactose intolerance and hypoglycemia, causes and symptoms of diabetes mellitus, and classification of diabetes into type 1 and type 2. The key topics covered include glucose regulation by insulin and glucagon, glucose metabolism pathways in the body, and abnormalities related to carbohydrate metabolism and diabetes.
This is a brief account of the fate of fats (fatty acids and glycerol) from the time of ingestion to its transport to body cells (before fatty acid oxidation).
These are major source of energy for living organisms.
Supplying a huge array of metabolic intermediates for biosynthetic reactions.
The structural elements in cell coat or connective tissues.
The brain has an extremely high metabolic demand, utilizing 20% of total oxygen and glucose consumption despite making up only 2% of body weight. The majority of this energy is used to maintain membrane potentials through ion transport mechanisms like the sodium-potassium pump. The brain relies almost exclusively on glucose as an energy source, consuming around 120 grams per day. While fatty acids cannot cross the blood-brain barrier, the brain can derive up to 50% of its energy from ketone bodies during prolonged starvation after three weeks of adaptation. Neurons primarily use lactate and pyruvate produced by astrocytes as an energy source rather than glucose. Astrocytes also play a key role in recycling the neurotransmitter glutamate and producing
This document summarizes the metabolic pathways of gluconeogenesis and glycogenolysis. It explains that gluconeogenesis synthesizes glucose from non-carbohydrate precursors through a series of steps that are largely the reverse of glycolysis, with three bypass reactions. Glycogenolysis breaks down glycogen stores in the liver and muscle into glucose through cleavage of glucose monomers by glycogen phosphorylase and subsequent conversion to glucose-6-phosphate. Both pathways are regulated by hormones like glucagon and epinephrine.
1. Glycogenesis is the process of glycogen synthesis, the storage form of carbohydrates in animals and plants.
2. Glycogen is synthesized from glucose-1-phosphate through the addition of glucose units via alpha-1,4 glycosidic bonds and branching via alpha-1,6 bonds, forming a branched polymer structure.
3. Glycogenesis occurs primarily in the liver and muscles, with liver glycogen functioning to regulate blood glucose levels between meals through glycogenolysis and export of glucose, while muscle glycogen provides glucose for local glycolysis.
Clinical significance of carbohydrates presentation130144011
The document discusses carbohydrates of biological and clinical significance and glucose absorption. It covers classification of carbohydrates, their biological and clinical importance, digestion and absorption of glucose through sodium-glucose cotransporters, and important glucose transporters. The seminar objectives were to discuss carbohydrate structure and function, glucose homeostasis, dietary fiber significance, and digestion and absorption of carbohydrates. Key topics included biological roles of carbohydrates, clinical implications such as glycated hemoglobin, and the five phase mechanism of glucose homeostasis.
Metabolism of amino acids (general metabolism)Ashok Katta
Metabolism of amino acids (general metabolism).
Part - I of amino acid metabolism.
This presentation covers Transamination, deamination, formation and Transport of Ammoniaand etc.
Unit 7 : Carbohydrates metabolism & disordersDrElhamSharif
This document provides an overview of carbohydrate metabolism and disorders by Dr. Elham Sharif. It covers objectives, carbohydrate classification and functions, glucose metabolism pathways, hormonal control of glucose levels, normal blood glucose and urine glucose levels, hormones that affect blood glucose, abnormalities in carbohydrate metabolism including lactose intolerance and hypoglycemia, causes and symptoms of diabetes mellitus, and classification of diabetes into type 1 and type 2. The key topics covered include glucose regulation by insulin and glucagon, glucose metabolism pathways in the body, and abnormalities related to carbohydrate metabolism and diabetes.
This is a brief account of the fate of fats (fatty acids and glycerol) from the time of ingestion to its transport to body cells (before fatty acid oxidation).
These are major source of energy for living organisms.
Supplying a huge array of metabolic intermediates for biosynthetic reactions.
The structural elements in cell coat or connective tissues.
The brain has an extremely high metabolic demand, utilizing 20% of total oxygen and glucose consumption despite making up only 2% of body weight. The majority of this energy is used to maintain membrane potentials through ion transport mechanisms like the sodium-potassium pump. The brain relies almost exclusively on glucose as an energy source, consuming around 120 grams per day. While fatty acids cannot cross the blood-brain barrier, the brain can derive up to 50% of its energy from ketone bodies during prolonged starvation after three weeks of adaptation. Neurons primarily use lactate and pyruvate produced by astrocytes as an energy source rather than glucose. Astrocytes also play a key role in recycling the neurotransmitter glutamate and producing
This document summarizes the metabolic pathways of gluconeogenesis and glycogenolysis. It explains that gluconeogenesis synthesizes glucose from non-carbohydrate precursors through a series of steps that are largely the reverse of glycolysis, with three bypass reactions. Glycogenolysis breaks down glycogen stores in the liver and muscle into glucose through cleavage of glucose monomers by glycogen phosphorylase and subsequent conversion to glucose-6-phosphate. Both pathways are regulated by hormones like glucagon and epinephrine.
1. Glycogenesis is the process of glycogen synthesis, the storage form of carbohydrates in animals and plants.
2. Glycogen is synthesized from glucose-1-phosphate through the addition of glucose units via alpha-1,4 glycosidic bonds and branching via alpha-1,6 bonds, forming a branched polymer structure.
3. Glycogenesis occurs primarily in the liver and muscles, with liver glycogen functioning to regulate blood glucose levels between meals through glycogenolysis and export of glucose, while muscle glycogen provides glucose for local glycolysis.
Amino acids of biological importance 2021Ayman Hany
This document discusses amino acids and proteins of biological importance. It defines amino acids as organic acids that contain one or more amino groups. Proteins are formed from chains of 50 or more amino acids linked by peptide bonds. The document classifies amino acids and discusses the structures of proteins including primary, secondary, tertiary and quaternary structure. It also addresses the denaturation and conformational classification of proteins.
the presentation contain ways used to estimate proteins, this presentation prepared by TONNYBITE, a student from KILIMANJARO CHRISTIAN MEDICAL UNIVERSITY COLLEGE, TANZANIA
Glycolysis is a 10 step pathway that converts glucose into two pyruvate molecules and produces a net yield of two ATP molecules. It involves an energy-investment phase where ATP is used to phosphorylate intermediates and an energy-generation phase where ATP is produced from the oxidation of glyceraldehyde 3-phosphate. Glycolysis is the first step in both aerobic cellular respiration and anaerobic fermentation.
Glycogenolysis, process by which glycogen, the primary carbohydrate stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting. These slides will provide you detail explanation of Glycogenolysis.
Gluconeogenesis- Steps, Regulation and clinical significanceNamrata Chhabra
Gluconeogenesis- Thermodynamic barriers, substrates of gluconeogenesis, reciprocal regulation of glycolysis and gluconeogenesis, biological and clinical significance
This document summarizes several pathways involved in carbohydrate metabolism. It describes the hexose monophosphate pathway (HMP pathway), which provides an alternative route for glucose metabolism and is significant for biosynthesis of NADPH and pentose sugars. It does not consume or produce ATP. The document also summarizes the gamma amino butyrate (GABA) shunt, which converts glutamate to succinate via GABA. Finally, it provides an overview of glycogen metabolism, describing glycogen synthesis from glucose and glycogen breakdown into glucose.
The document summarizes the Krebs cycle, also known as the citric acid cycle or TCA cycle. It describes the cycle as a series of reactions that occur in mitochondria resulting in the oxidation of acetyl CoA to produce carbon dioxide, hydrogen atoms, and high-energy electron carriers. The cycle contains 8 enzyme-mediated steps that ultimately generate 3 NADH molecules, 1 FADH2, 1 GTP/ATP, and 2 CO2 per turn of the cycle. The cycle plays a key role in aerobic respiration by generating electron carriers that feed into the electron transport chain to produce ATP.
This document provides information about glycolysis, including:
1) Glycolysis involves the breakdown of glucose into pyruvate, producing 2 ATP and 2 NADH. There are 10 enzyme-catalyzed reactions in two stages.
2) Key regulatory enzymes include hexokinase, phosphofructokinase, and pyruvate kinase which control the flux of glycolysis.
3) Under anaerobic conditions, NADH is regenerated through lactic acid or ethanol fermentation to allow glycolysis to continue.
The document summarizes fatty acid biosynthesis. Fatty acids are synthesized predominantly in the liver, kidney, and adipose tissue through a three stage process. In the first stage, acetyl CoA and NADPH are produced in the mitochondria and transferred to the cytosol. In the second stage, malonyl CoA is formed from acetyl CoA. In the third stage, fatty acid synthase complex containing seven polypeptides catalyzes the reactions of fatty acid synthesis through condensation, carbonyl group reduction, dehydration, and double bond reduction to form fatty acids from acetyl CoA and malonyl CoA.
The cell membrane, also called the plasma membrane, is a biological membrane that separates the interior of a cell from the outside environment. It is composed primarily of lipids and proteins arranged in a fluid mosaic structure. The lipid bilayer that forms the foundation of the cell membrane is made up of phospholipids with hydrophilic heads and hydrophobic tails. Embedded within this bilayer are transmembrane and peripheral proteins that perform important functions like selective transport, cell signaling, and providing anchoring sites. The fluid mosaic model proposed by Singer and Nicolson in 1972 is widely accepted as it accounts for the fluid and dynamic nature of the cell membrane.
The document discusses lipids and fatty acids. It defines lipids as a heterogeneous group of compounds related more by physical than chemical properties, that are relatively insoluble in water but soluble in nonpolar solvents. Fatty acids are aliphatic carboxylic acids that occur mainly as esters in natural fats and oils. They can be classified as saturated or unsaturated based on whether they contain double bonds. Common saturated fatty acids include palmitic acid and stearic acid, while monounsaturated fatty acids include oleic acid. Polyunsaturated fatty acids contain two or more double bonds and important examples are linoleic acid and alpha-linolenic acid.
Diversity of cell size & shape By KK Sahu SirKAUSHAL SAHU
Cells show tremendous diversity in size, shape, structure and function. Robert Hooke first observed cells in 1665 when examining a thin slice of cork under a microscope. Cells can be prokaryotic or eukaryotic, and range enormously in size from 0.1um to over 2m in length. Cell shape also varies greatly between species, with spherical, flat, elongated and branched shapes that often correlate to a cell's specialized function. This diversity arises from cells differentiating and specializing during development to perform distinct roles in multicellular organisms.
This document summarizes several common chemical tests used to detect carbohydrates, including Fehling's reagent, Benedict's reagent, Barfoed's reagent, and the Molisch test. It also describes methods for reducing sugars using sodium amalgam, strong acids, and dilute alkalies. These tests and reduction methods allow distinguishing between mono- and disaccharides and identifying "reducing" sugars that give positive tests without prior hydrolysis.
Glycolysis is the breakdown of glucose to pyruvate through a series of enzyme-catalyzed reactions. It occurs in the cytosol and consists of a preparatory phase requiring ATP and a payoff phase generating ATP. Key steps include phosphorylation by hexokinase, aldolase cleavage, substrate-level phosphorylation by phosphoglycerate kinase, and pyruvate formation by pyruvate kinase. Glycolytic enzymes are regulated by feedback inhibition and metabolites like fructose 2,6-bisphosphate and AMP/ATP ratios to control flux through the pathway.
This document summarizes the glucuronic acid pathway, an alternative oxidative pathway for glucose metabolism. It provides UDP-glucuronic acid, which is used to conjugate bilirubin, steroids, and drugs to make them more water soluble and excretable. The pathway also synthesizes glycosaminoglycans and is involved in vitamin C synthesis in many animals. Key steps include the conversion of glucose-6-phosphate to UDP-glucuronate and the subsequent production of L-gulonate, a precursor for ascorbic acid synthesis. Certain genetic disorders can cause excess excretion of metabolites from this pathway such as L-xylulose in essential pentosuria.
Lipid metabolism is the synthesis and degradation of lipids in cells.
It involves the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes.
In animals, these fats are obtained from food or synthesized by the liver.
This document discusses various disorders of lipid metabolism. It begins by describing Fredrickson's classification of hyperlipidemias. It then discusses specific disorders in more detail, including chylomicron syndrome, familial hypercholesterolemia, familial defective apoB3500, familial combined hyperlipidemia, familial hypertriglyceridemia, type III hyperlipoproteinemia, and polygenic hypercholesterolemia. For each disorder, it provides information on prevalence, genetic factors, clinical presentation, diagnostic criteria, and treatment approaches.
1) Organisms require chemical energy stored in high-energy compounds for processes like muscle contraction and active transport.
2) High-energy compounds include ATP, phosphoenolpyruvate, and acetyl-CoA, which contain high-energy bonds like phosphoanhydride and thioester bonds.
3) ATP is the most common energy currency in cells. It stores and transports chemical energy through its high-energy phosphoanhydride bonds, which are hydrolyzed to fuel energetic reactions.
Metabolism refers to all chemical reactions that occur in living cells and are catalyzed by enzymes. These reactions allow cells to release energy from food, build macromolecules, and respond to hormones and vitamins. There are three main types of metabolic pathways: anabolic pathways that build complex molecules, catabolic pathways that break down molecules to release energy, and amphibolic pathways that can be either anabolic or catabolic. A key molecule in metabolism is ATP, which acts as an energy carrier as it is able to donate its high-energy phosphate during reactions. The process of oxidative phosphorylation in the mitochondrial respiratory chain uses redox reactions to generate a proton gradient that drives the synthesis of ATP from ADP and phosphate.
GLYCOGENOLYSIS & REGULATION OF GLYCOGEN METABOLISMYESANNA
- Glycogenolysis is the degradation of glycogen stores in the liver and muscle into glucose. It is carried out by independent cytosolic enzymes.
- Glycogen phosphorylase breaks alpha-1,4 glycosidic bonds in glycogen, producing glucose-1-phosphate. A debranching enzyme then breaks alpha-1,6 bonds to fully degrade glycogen.
- Glucose-1-phosphate is converted to glucose-6-phosphate which can be further converted to glucose by glucose-6-phosphatase in the liver, releasing it into circulation. Muscle lacks this enzyme and uses its glucose-6-phosphate in glycolysis.
- Glycogen metabolism is regulated by hormones like
B.Sc. Biochemistry II Cellular Biochemistry Unit 2 Cellular componentsRai University
This document provides information on the ultrastructure of cells. It discusses the organelles found within eukaryotic cells like the nucleus, which contains DNA and RNA, and the nuclear envelope that surrounds it. It also describes mitochondria, which generate energy for the cell, and chloroplasts in plant cells, which use chlorophyll and photosynthesis to harness energy from sunlight. Finally, it mentions the endoplasmic reticulum and ribosomes, which are involved in protein synthesis.
Animal cells are eukaryotic cells or cells with a membrane-bound nucleus.
DNA in animal cells is housed within the nucleus.
In addition to having nucleus animal cells also contain other membrane-bound organelles.
Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for animal cells.
All living things are made up of cells that make up their body structure. Some of these living things are single-celled and other organisms are made up of more than one cell.
Amino acids of biological importance 2021Ayman Hany
This document discusses amino acids and proteins of biological importance. It defines amino acids as organic acids that contain one or more amino groups. Proteins are formed from chains of 50 or more amino acids linked by peptide bonds. The document classifies amino acids and discusses the structures of proteins including primary, secondary, tertiary and quaternary structure. It also addresses the denaturation and conformational classification of proteins.
the presentation contain ways used to estimate proteins, this presentation prepared by TONNYBITE, a student from KILIMANJARO CHRISTIAN MEDICAL UNIVERSITY COLLEGE, TANZANIA
Glycolysis is a 10 step pathway that converts glucose into two pyruvate molecules and produces a net yield of two ATP molecules. It involves an energy-investment phase where ATP is used to phosphorylate intermediates and an energy-generation phase where ATP is produced from the oxidation of glyceraldehyde 3-phosphate. Glycolysis is the first step in both aerobic cellular respiration and anaerobic fermentation.
Glycogenolysis, process by which glycogen, the primary carbohydrate stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting. These slides will provide you detail explanation of Glycogenolysis.
Gluconeogenesis- Steps, Regulation and clinical significanceNamrata Chhabra
Gluconeogenesis- Thermodynamic barriers, substrates of gluconeogenesis, reciprocal regulation of glycolysis and gluconeogenesis, biological and clinical significance
This document summarizes several pathways involved in carbohydrate metabolism. It describes the hexose monophosphate pathway (HMP pathway), which provides an alternative route for glucose metabolism and is significant for biosynthesis of NADPH and pentose sugars. It does not consume or produce ATP. The document also summarizes the gamma amino butyrate (GABA) shunt, which converts glutamate to succinate via GABA. Finally, it provides an overview of glycogen metabolism, describing glycogen synthesis from glucose and glycogen breakdown into glucose.
The document summarizes the Krebs cycle, also known as the citric acid cycle or TCA cycle. It describes the cycle as a series of reactions that occur in mitochondria resulting in the oxidation of acetyl CoA to produce carbon dioxide, hydrogen atoms, and high-energy electron carriers. The cycle contains 8 enzyme-mediated steps that ultimately generate 3 NADH molecules, 1 FADH2, 1 GTP/ATP, and 2 CO2 per turn of the cycle. The cycle plays a key role in aerobic respiration by generating electron carriers that feed into the electron transport chain to produce ATP.
This document provides information about glycolysis, including:
1) Glycolysis involves the breakdown of glucose into pyruvate, producing 2 ATP and 2 NADH. There are 10 enzyme-catalyzed reactions in two stages.
2) Key regulatory enzymes include hexokinase, phosphofructokinase, and pyruvate kinase which control the flux of glycolysis.
3) Under anaerobic conditions, NADH is regenerated through lactic acid or ethanol fermentation to allow glycolysis to continue.
The document summarizes fatty acid biosynthesis. Fatty acids are synthesized predominantly in the liver, kidney, and adipose tissue through a three stage process. In the first stage, acetyl CoA and NADPH are produced in the mitochondria and transferred to the cytosol. In the second stage, malonyl CoA is formed from acetyl CoA. In the third stage, fatty acid synthase complex containing seven polypeptides catalyzes the reactions of fatty acid synthesis through condensation, carbonyl group reduction, dehydration, and double bond reduction to form fatty acids from acetyl CoA and malonyl CoA.
The cell membrane, also called the plasma membrane, is a biological membrane that separates the interior of a cell from the outside environment. It is composed primarily of lipids and proteins arranged in a fluid mosaic structure. The lipid bilayer that forms the foundation of the cell membrane is made up of phospholipids with hydrophilic heads and hydrophobic tails. Embedded within this bilayer are transmembrane and peripheral proteins that perform important functions like selective transport, cell signaling, and providing anchoring sites. The fluid mosaic model proposed by Singer and Nicolson in 1972 is widely accepted as it accounts for the fluid and dynamic nature of the cell membrane.
The document discusses lipids and fatty acids. It defines lipids as a heterogeneous group of compounds related more by physical than chemical properties, that are relatively insoluble in water but soluble in nonpolar solvents. Fatty acids are aliphatic carboxylic acids that occur mainly as esters in natural fats and oils. They can be classified as saturated or unsaturated based on whether they contain double bonds. Common saturated fatty acids include palmitic acid and stearic acid, while monounsaturated fatty acids include oleic acid. Polyunsaturated fatty acids contain two or more double bonds and important examples are linoleic acid and alpha-linolenic acid.
Diversity of cell size & shape By KK Sahu SirKAUSHAL SAHU
Cells show tremendous diversity in size, shape, structure and function. Robert Hooke first observed cells in 1665 when examining a thin slice of cork under a microscope. Cells can be prokaryotic or eukaryotic, and range enormously in size from 0.1um to over 2m in length. Cell shape also varies greatly between species, with spherical, flat, elongated and branched shapes that often correlate to a cell's specialized function. This diversity arises from cells differentiating and specializing during development to perform distinct roles in multicellular organisms.
This document summarizes several common chemical tests used to detect carbohydrates, including Fehling's reagent, Benedict's reagent, Barfoed's reagent, and the Molisch test. It also describes methods for reducing sugars using sodium amalgam, strong acids, and dilute alkalies. These tests and reduction methods allow distinguishing between mono- and disaccharides and identifying "reducing" sugars that give positive tests without prior hydrolysis.
Glycolysis is the breakdown of glucose to pyruvate through a series of enzyme-catalyzed reactions. It occurs in the cytosol and consists of a preparatory phase requiring ATP and a payoff phase generating ATP. Key steps include phosphorylation by hexokinase, aldolase cleavage, substrate-level phosphorylation by phosphoglycerate kinase, and pyruvate formation by pyruvate kinase. Glycolytic enzymes are regulated by feedback inhibition and metabolites like fructose 2,6-bisphosphate and AMP/ATP ratios to control flux through the pathway.
This document summarizes the glucuronic acid pathway, an alternative oxidative pathway for glucose metabolism. It provides UDP-glucuronic acid, which is used to conjugate bilirubin, steroids, and drugs to make them more water soluble and excretable. The pathway also synthesizes glycosaminoglycans and is involved in vitamin C synthesis in many animals. Key steps include the conversion of glucose-6-phosphate to UDP-glucuronate and the subsequent production of L-gulonate, a precursor for ascorbic acid synthesis. Certain genetic disorders can cause excess excretion of metabolites from this pathway such as L-xylulose in essential pentosuria.
Lipid metabolism is the synthesis and degradation of lipids in cells.
It involves the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes.
In animals, these fats are obtained from food or synthesized by the liver.
This document discusses various disorders of lipid metabolism. It begins by describing Fredrickson's classification of hyperlipidemias. It then discusses specific disorders in more detail, including chylomicron syndrome, familial hypercholesterolemia, familial defective apoB3500, familial combined hyperlipidemia, familial hypertriglyceridemia, type III hyperlipoproteinemia, and polygenic hypercholesterolemia. For each disorder, it provides information on prevalence, genetic factors, clinical presentation, diagnostic criteria, and treatment approaches.
1) Organisms require chemical energy stored in high-energy compounds for processes like muscle contraction and active transport.
2) High-energy compounds include ATP, phosphoenolpyruvate, and acetyl-CoA, which contain high-energy bonds like phosphoanhydride and thioester bonds.
3) ATP is the most common energy currency in cells. It stores and transports chemical energy through its high-energy phosphoanhydride bonds, which are hydrolyzed to fuel energetic reactions.
Metabolism refers to all chemical reactions that occur in living cells and are catalyzed by enzymes. These reactions allow cells to release energy from food, build macromolecules, and respond to hormones and vitamins. There are three main types of metabolic pathways: anabolic pathways that build complex molecules, catabolic pathways that break down molecules to release energy, and amphibolic pathways that can be either anabolic or catabolic. A key molecule in metabolism is ATP, which acts as an energy carrier as it is able to donate its high-energy phosphate during reactions. The process of oxidative phosphorylation in the mitochondrial respiratory chain uses redox reactions to generate a proton gradient that drives the synthesis of ATP from ADP and phosphate.
GLYCOGENOLYSIS & REGULATION OF GLYCOGEN METABOLISMYESANNA
- Glycogenolysis is the degradation of glycogen stores in the liver and muscle into glucose. It is carried out by independent cytosolic enzymes.
- Glycogen phosphorylase breaks alpha-1,4 glycosidic bonds in glycogen, producing glucose-1-phosphate. A debranching enzyme then breaks alpha-1,6 bonds to fully degrade glycogen.
- Glucose-1-phosphate is converted to glucose-6-phosphate which can be further converted to glucose by glucose-6-phosphatase in the liver, releasing it into circulation. Muscle lacks this enzyme and uses its glucose-6-phosphate in glycolysis.
- Glycogen metabolism is regulated by hormones like
B.Sc. Biochemistry II Cellular Biochemistry Unit 2 Cellular componentsRai University
This document provides information on the ultrastructure of cells. It discusses the organelles found within eukaryotic cells like the nucleus, which contains DNA and RNA, and the nuclear envelope that surrounds it. It also describes mitochondria, which generate energy for the cell, and chloroplasts in plant cells, which use chlorophyll and photosynthesis to harness energy from sunlight. Finally, it mentions the endoplasmic reticulum and ribosomes, which are involved in protein synthesis.
Animal cells are eukaryotic cells or cells with a membrane-bound nucleus.
DNA in animal cells is housed within the nucleus.
In addition to having nucleus animal cells also contain other membrane-bound organelles.
Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for animal cells.
All living things are made up of cells that make up their body structure. Some of these living things are single-celled and other organisms are made up of more than one cell.
Cell: The cell is the ultimate structural and functional unit of the body.
The three principal constituents of the cell are:
1. Cell membrane
2. Cytoplasm and its organelles
3. Nucleus
The document provides an overview of plant cell structure and function. It describes the basic components of plant cells, including the cell wall, cell membrane, nucleus, chloroplasts, mitochondria, ribosomes, Golgi complex, endoplasmic reticulum, and central vacuole. It explains the structure and functions of each organelle. For example, it states that chloroplasts contain chlorophyll and are the site of photosynthesis, performing both the light-dependent and light-independent reactions. The mitochondria are described as the powerhouses of the cell, where cellular respiration and ATP production occur.
DEFINITION:
Cell is a structural and functional unit of all living organisms.
STRUCTURE OF THE CELL:
PARTS OF THE CELL
Plasma Membrane
Cytoplasm
a. Cytosol
b. Organelles
Cytoskeleton
Endoplasmic Reticulum
Golgi Apparatus
Lysosome
Centrosome
Nucleus
Mitochondria
PLASMA MEMBRANE
Structure of Plasma Membrane
The Cell membrane also known as the Plasma membrane.
It is a Biological Membrane that separates the interior of all cells from the
outside environment.
It consists of a lipid bilayer with embedded proteins.
The Lipid layer made up of three types of lipid molecules such as Phospholipids,
Cholesterols and Glycolipids.
The bilayer arrangement occurs because the lipid are amphipathic molecule
(Both Polar and Nonpolar parts)
Phospholipids – Phosphate (Polar) – Head – Hydrophilic
Lipid (Non Polar) – Tail – Hydrophobic
Cholesterols – Slightly Amphipathic
Glycolipids – Carbohydrate (Polar) – Head
Lipid (Non Polar) – Tail
Functions of Plasma Membrane:
Acts as a barrier separating inside and outside of the cell.
Controls the flow of substances into and out of the cell.
Helps identify the cell to other cells (e.g., immune cells).
Participates in intercellular signalling.
CYTOPLASM
Cytoplasm consists of all the cellular contents between the plasma membrane
and the nucleus and has two components.
a) Cytosol
b) Organelles
a) Cytosol: (pH - 7)
The Cytosol (Intracellular fluid) is the fluid portion of the cytoplasm that
surrounds organelles.
Cytosol is 75 – 90% of water plus various dissolved and suspended components.
Among these are different types of ions, glucose, amino acid, fatty acid, protein,
lipid, ATP and waste products.
The cytosol is the site of many Chemical reactions for a cell existence.
b) Organelles
Cytoskeleton
Endoplasmic Reticulum
Golgi Apparatus
Lysosome
Centrosome
Nucleus
Mitochondria
CYTOSKELETON:
The cytoskeleton is a network of protein filaments.
It Consists of three types of filament proteins
1. Microfilament
2. Intermediate filament
3. Microtubules
1. Microfilament
Microfilaments are the thinnest elements of the cytoskeleton.
Diameter – 6nm
They are composed of protein Actin and Myosin.
Most Prevalent at the edge of a cell.
Functions of Microfilament:
They help generate movement and provide mechanical support.
Microfilaments are involved in muscle contraction, cell division and cell
locomotion.
The Mechanical support that is responsible for the basic strength and shape of
cells.
2. Intermediate filaments
Several different proteins such as keratin, collagen can compose intermediate
filament.
Diameter – 10 nm
Functions of Intermediate filaments:
They help stabilize the position of organelles such as the nucleus.
3. Microtubules
Largest cytoskeletal components.
Diameter – 25 nm
Unbranched hollow tubes composed mainly of the protein tubulin.
Functions of Microtubules
Microtubules help determine Cell shape.
The document discusses the key differences between prokaryotic and eukaryotic cells. It explains that prokaryotic cells lack a nucleus and organelles, while eukaryotic cells have a well-defined nucleus surrounded by a membrane as well as various intracellular organelles like mitochondria and chloroplasts. The document also covers cell transport mechanisms, including passive diffusion, facilitated diffusion, and active transport which uses ATP.
The cell membrane is composed of a lipid bilayer with embedded proteins. The lipid bilayer is fluid and allows only fat-soluble substances to pass through. Integral proteins span the membrane while peripheral proteins are attached to surfaces. Membrane proteins function in transport, structure, signaling and more. Carbohydrates attached to proteins and lipids form the glycocalyx and function in cell recognition and selective permeability. The cell membrane protects the cell, regulates what enters and exits, and maintains the cell's shape and size.
The document summarizes the key components and structures of plant cells. It describes the cell wall, cell membrane, plasmodesmata, nuclear membrane, nucleus, vacuole, cytoplasm, plastids, mitochondria, endoplasmic reticulum, Golgi apparatus, ribosomes, microbodies, microtubules, and microfilaments. Each plays an important role in functions like protection, structure, transport, photosynthesis, protein production, and cell structure.
The document summarizes the structure and functions of key organelles in plant cells, including the cell wall, plasma membrane, nucleus, chloroplasts, mitochondria, Golgi apparatus, endoplasmic reticulum, vacuoles, cytoskeleton, and plasmodesmata. The cell wall provides shape and protection, while the plasma membrane encloses the living contents of the cell. The nucleus houses genetic material and controls cell processes. Chloroplasts and mitochondria perform photosynthesis and respiration. Other organelles are involved in transport and sorting of materials within the cell.
The document discusses the roles of molecular chaperones in facilitating protein import from the cytosol into mitochondria and chloroplasts, which are double-membraned organelles. Mitochondria and chloroplasts require most of their proteins to be synthesized in the cytosol and translocated across membranes. Molecular chaperones play critical roles in ensuring these imported proteins fold properly and are directed to their correct destinations utilizing transport complexes and channels. Tight coordination is needed for the biogenesis and maintenance of mitochondria and chloroplasts given the numerous compartments and energetic barriers involved in protein transcription, translation and import.
The document provides information about the structure and functions of human cells and their organelles. It discusses that cells contain organelles like the cell membrane, nucleus, mitochondria, endoplasmic reticulum, ribosomes, Golgi apparatus, and lysosomes. It describes the roles of these organelles, such as the mitochondria generating energy, the endoplasmic reticulum synthesizing proteins and lipids, and ribosomes producing proteins.
cells structure and transport mechanismsReisa Roberts
The document provides detailed information about the structure and functions of eukaryotic and prokaryotic cells. Eukaryotic cells are larger and more complex than prokaryotic cells, containing a nucleus and membrane-bound organelles. Organelles such as mitochondria and chloroplasts are thought to have originated from endosymbiotic prokaryotes. The cell membrane controls what enters and exits the cell and is composed of phospholipids and proteins. Materials can move across the membrane through diffusion, osmosis, facilitated diffusion, active transport, or vesicles.
The document summarizes key aspects of cell physiology:
- Cells are the basic units of structure and function in the body, with over 100 trillion cells that come in a variety of shapes and sizes.
- All cells share certain characteristics like mechanisms for obtaining and using energy from nutrients.
- The basic structures of cells include a plasma membrane, cytoplasm containing organelles like the nucleus, mitochondria and ribosomes, and the nucleus which houses genetic material.
- The plasma membrane is selectively permeable and controls what enters and exits the cell. It contains proteins, lipids and carbohydrates.
- The cytoplasm and organelles work together to carry out specialized functions and transport materials within the cell.
- The nucleus contains
Cells are the basic unit of life and come in two main types - prokaryotic and eukaryotic. Eukaryotic cells are generally larger and more complex, containing membrane-bound organelles like the nucleus and mitochondria. Organelles specialize cells to carry out specific functions like protein production or energy generation. Cells range in size from a few microns to over a meter in some plant and animal cells.
All about cells !!!!!!!!!!!!!!!!!!!!!!!!!!!!!arivuselvi3
Animal cells are the basic unit of life in animals. They are eukaryotic cells that lack a cell wall and contain a nucleus and other organelles that carry out specialized functions. Unlike plant cells, animal cells do not contain chloroplasts and must obtain nutrients from external sources. The organelles in animal cells include the mitochondria, which produce energy, and the endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, and other structures that help the cell carry out its functions. Animal cells are typically diploid and undergo meiosis to produce haploid gametes during sexual reproduction.
Cell structure includes three main parts - the cell membrane, cytoplasm and organelles, and the nucleus. The cell membrane is a thin double layer that encloses the cell. The cytoplasm contains various organelles that carry out specific functions like protein synthesis, energy production, and waste removal. Prominent organelles include the endoplasmic reticulum, mitochondria, Golgi complex and ribosomes. The nucleus is the largest organelle and houses the cell's genetic material in the form of chromatin and chromosomes.
cell organelles, nucleus, mitochondria, plasma memebrane,ribosomes, golgi bodies, lysosomes, chloroplast
(helpfull for B.Sc. students as well as competitions tests
1. The document discusses the structure and function of eukaryotic cells and their organelles. It describes the plasma membrane, mitochondria, nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, and cytoskeleton.
2. Key organelles include the mitochondria, which produces ATP through oxidative phosphorylation, and the nucleus, which contains DNA and directs protein synthesis.
3. The cytoskeleton is composed of microfilaments, microtubules, and intermediate filaments which help maintain cell shape and enable cell movement.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
MATATAG CURRICULUM: ASSESSING THE READINESS OF ELEM. PUBLIC SCHOOL TEACHERS I...NelTorrente
In this research, it concludes that while the readiness of teachers in Caloocan City to implement the MATATAG Curriculum is generally positive, targeted efforts in professional development, resource distribution, support networks, and comprehensive preparation can address the existing gaps and ensure successful curriculum implementation.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
11. The nuclear envelope is perforated by pores (3000-4000), which facilitate communication between the nucleus and the cytoplasm.
12. Attached to the outer membrane of the nuclear envelope are polyribosomes.
13.
14.
15. Organelles are metabolically active, permanent residents of the cell which survive cell division i.e. they reappear in the daughter cells following cell division.
16.
17. Inclusion bodies are the transitory residents of the cytoplasm not involved in cell metabolism and do not survive cell division.
18. They comprise mainly accumulated metabolites, lipid droplets, pigments and minerals and are sporadically distributed in body cells.
19.
20. Functions of the Cell Membrane (Plasmalemma) Communication through receptors on the outer surface Intercellular connectivity which facilitates boundary flexibility, support of cell structure and protects cellular contents. Provision of physical barrier between the intra and extra cellular compartments. Selective permeability which regulates entry/exit of materials across the membrane.
22. Mitochondria are membrane-bound enzyme storage organelles. Mitochondrial enzymes are involved in aerobic respiration, production of ATP and heat energy for maintenance of body temperature. It is enclosed in two sheets of membrane. An outer sieve-like unfolded membrane and an inner membrane which is thrown into long finger-like folds called cristae.
23. The number of cristae corresponds to the cell’s energy needs. The space between the two membranes is the intermembranous space while the space deep to the inner membrane is referred to as the matrix. Mitochondria are eosinophilic, elongated rod-like organelles measuring 0.5 to 1 microns in diameter and 5 to 10 microns in length.
24. The Matrix also contains chromosomes DNA, ribosomes, messenger RNA and Transfer RNA which are utilized in the synthesis of small amount of proteins for use within the matrix. They are wildly distributed in all cells but occur abundantly in cells with very high energy needs (Heart, muscles and kidney cells). Integral proteins of the outer and inner membrane provide channels for selective passage of small molecules, whiles enzymes in the matrix and on the surface of the inner membrane are involved in the production of ATP for the cell.
25. However the bulk of the proteins required in the mitochondrion is synthesised in the cytosol. The mitochondrial matrix also contains granules which store calcium ions. The mitochondrion produces about 100 molecules of ATP per second
27. Ribosomes are small, electron-dense particles not enclosed in membrane and are located in the cytosol. Measure about 20-30 nanometres they are basophilic and stained by all basic dyes Ribosome is composed of rRNA and about 80 different proteins. It usually occur in two subunits, large and small subunits. The rRNA of the ribosome is synthesised in the nucleus while its protein is synthesised in the cytosol.
28. Ribosomes are involved in protein synthesis. While cytosolic proteins (free proteins) are synthesised by polyribosomes, secretory and endoplasmic reticulum proteins are synthesised on the membrane of rough endoplasmic reticulum Ribosomes occur in three forms: In isolated particles Assembled in cluster on mRNA strand to form Polyribosomes Adsorbed to the membrane of endoplasmic reticulum through their large subunit to form Rough Endoplasmic Reticulum. Protein synthesis by ribosomes also implicates: mRNA, tRNA and rRNA.
30. Contains up to 40 different acid Hydrolytic enzymes (pH – 5). Site of intracellular digestion. Site of turnover of cellular components Found in cells involved in extensive phagocytic activities e.g. Macrophages and Neutrophil Used for intralysosomal digestion. For Extracellular digestion/destruction e.g. osteoclast breakdown of bone matrix. Metabolism of several substrate all over the body.
32. This organelle is made up of anastomosing network of intercommunicating channels/cisternae/sacs Enclosed in a continuous membrane. Occurs in two forms, namely Rough and Smooth which are also interconnected. Cisternae of smooth ER are tubular in shape. Cisternae of Rough ER are flattened. The roughness on the surface of rough ER is due to the adsorption of polyribosomes on their outer surface. Polyribosome also impacts the basophilic staining characteristic on RER. Its membrane is continuous with that of the nuclear envelope.
33. Distribution and Functions of RER RER is prominent in protein synthesising cells such as; Pancreatic acinar cells, cells of the endocrine glands, plasma cells, fibroblast etc. Proteins synthesised in RER are stored in Lysosomes or granules; stored temporarily before exocytosis or used as integral membrane proteins.
34. Smooth Endoplasmic Reticulum (SER) This is ER not bund to polyribosomes but continuous with RER and are less abundant is cell containing RER. Distribution and Functions of SER SER is found in all cells where they are involved in: The synthesis phospholipids and cholesterol used in all cellular membranes includingmembranes of organelles. They occur in abundance in other cells where they are involved in: Sequestration and release of Calcium ions a vital process in muscular contraction Biosynthesis of Lipids required for synthesis of steroid hormones Detoxification of potentially harmful compounds such as alcohol and barbiturates
35.
36. A complex of smooth membranous saccule usually located between the apical membrane and the nucleus of the secretory cell. Within its saccule are various enzymes implicated in processing proteins synthesised in the endoplasmic reticulum. The Golgi apparatus receives transport vesicles containing proteins from the endoplasmic reticulum and packages modified proteins into condensing vesicles for transportation to other organelle or to the cell membrane for release of modified proteins as secretory products. Protein modification occurring in the Golgi apparatus includes concentration, glycosylation, sulphation, phosphorylation and proteolysis.
37. THE CYTOSKELETON This is composed of a complex of microtubules, microfilaments (Actin Filaments), and Intermediate Filaments.
38. Microtubules These are tubular protein subunits involved in cellular shape, cell division, intra and extra cellular movements and transport of substances in the cytoplasm of the cell. Largest are 23-25nm in diameter Microtubules are widely distributed within the cytoplasm where they occur in various forms which include: Cytoplasmic microtubules for intracellular transport of materials including organelles Centrioles which are involved in cell division Mitotic spindles which are involved in cell division Cilia and Flagella which are motile structures implicated in cellular motion Basal bodies which are located at the bases of cilia and flagella and are involved in the configuration of these structures.
39. Microfilaments/Actin Filaments Microfilament is a double-stranded helix of globular protein subunits which is widely distributed in all body cells and is involved in: the structural integrity and contractility of the cell movement of organelles in the cytosol. cell cleavage during cell division. Smallest is 6-7nm Diameter
40. Actin filament is seen in two forms in the cell viz. polymerised F-Actin and free Globular G-Actin. F-Actin filaments are involved in: Muscular contraction in collaboration with myosin filants Cell shape integrity and locomotion (stress fibres of crawling cells) Movement of organelles and other cytosolic contents (cytoplasmic steaming) Cellular cleavage in mitotic cells
41. Intermediate Filaments Are intermediate in size to microtubules and microfilaments (10-12 nm in diameter). They are more stable structurally than Microtubules/filament and are composed of variable protein subunits depending on their localization and functions Examples of intermediate filaments include: Keratin of epithelial cell for strength and protection Vimentin of the mesenchymal cell for structural integrity Desmin of the muscle cell for structural integrity Neurofilament of the nerve cell for structural integrity Lamins of all cell nuclei also for structural integrity
42. Centrosome/Centrioles The centrosome is the region of the cytosol situated between the nucleus and the Golgi apparatus. It accommodates the Centrioles which are two cylindrical shaped microtubular structures oriented at right angles to one another. Each cylinder is made up of nine triplets of parallel microtubules. Centrioles are implicated in organising the microtubules of the cell as in the organization of mitotic spindles during cell division. They also form the basal bodies of cilia and flagella
43. PEROXISOME/MICROBODIES Are membrane-bound organelles which contain various enzymes and utilise oxygen without the production of ATP. Measuring about 0.5 microns in diameter they oxidise organic substrate by the removal of hydrogen ions, leading to the production of H2O2. This is immediately broken down by peroxisomal catalase to prevent its toxic effect on the cell. The oxygen atom released from this process is utilized in oxidation of other potentially toxic substances/drugs in the liver (Ethyl alcohol) and kidneys. Peroxisomes are also implicated in lipid metabolism (Beta oxidation of long-chain [18 carbon and over] fatty acids).
47. THE PLAMALEMMA (CELL MEMBRANE) STRUCTURE The Plasmalemma is the physical external boundary of the cell. It is composed of Phospholipids, Protein, Carbohydrate and Cholesterol which are intricately organised into a trilaminar structure. The cell membranes well as the membranes surrounding the organelles range from 7.5 to 10 nanometre in thickness.
48. The 3-layered structure, referred to as the Unit Membrane structure is formed from two phospholipid layers; the fatty acid nonpolar (Hydrophobic) tails of the two phospholipids are located in the middle layer while the polar (Hydrophilic) head are located on either side of the middle layer. The proteins of the cell membrane account for 50% (w/w) of the membrane and occur in two forms, viz. integral proteins which traverse the thickness of the membrane and peripheral proteins which are adsorbed to the outer or inner surfaces of the membrane.
49. While the peripheral proteins are involved in cell recognition and interactions, integral proteins regulate passage of material and active transport of specific molecules across the membrane The cholesterol embedded within the phospholipid fatty acid chains their movements and also modulates the fluidity and movements of other contents of the membrane. The carbohydrate contents of the membrane are attached to the lipids and proteins as glycolipids and glycoproteins respectively.
50. Some of the carbohydrates of the glycoprotein constitute the glycocalyx on the outer surface of the membrane. Others are receptors involved in adhesion, cell recognition and responses to protein hormones. Others yet are attached to the cytoskeletal components of the cytoplasm for maintenance of cell shape and integrity.
52. CHEMISTRY OF LIPIDS Lipids are heterogeneous group of naturally occurring compounds, relatively insoluble in water but freely soluble in non-polar organic solvents like, benzene, chloroform, ether and alcohol. Formed of long-chain hydrocarbon groups but may also contain oxygen, phosphorus, nitrogen and sulfur.
53. Functions Triglycerides are the major storage form of energy Provide essential fatty acids; phospholipids, hormones Form important constituents of cell membrane and helps to maintain the membrane structure and integrity Absorption of vitamin A, D, E and K depends needs presence lipids in the diet
54. The basic unit of lipids, acetyl CoA (the active form of acetic acid) is used for the synthesis of cholesterol and hence steroid hormones Its insulating effect has been utilized in the body for protecting internal organs from shock . Dipalmitoyl lecithin, a phospholipid act as surfactant and is required for the normal functioning of the lung alveoli Helps in blood coagulation
55. Properties of lipids Oils and fats (lipids) are similar in nature. Oils and lipids are different only in their physical property. Triglycerides, which contain a higher proportion of unsaturated fatty acid or short chain fatty acid, are liquid at 20°C and are usually called as oils, e.g. vegetable oils. Fats on the other hand are solid at room temperature and contain saturated long chain fatty acid e.g. animal fat.
56. LEARNING OBJECTIVE 5 DISCUSS TECHNIQUES USED FOR PREPARATION OF CELLS AND TISSUES FOR VIEWING UNDER A MICROSCOPE
57. Tissue Preparation for Light Microscopy 1st Step – Fixation to preserve structures (This process stops cell metabolism). Agents used for fixation include: Formaldehyde Alcohol (80%) Acetone Bouin’s fluid Carnoy’s fluid Rossman’s fluid Zenker’s fluid 2nd Step – Dehydration and Embedding in Paraffin. Specimen is prepared for Embedding in paraffin to permit Sectioning (specimen must be infiltrated with an embedding medium that allows it to be thinly sliced 5-15μm). This is done after fixation by passing the specimen through a series of alcohol solutions in ascending concentrating up to 100% to remove water (Dehydration).
58. 3rd Step - Clearing Organic solvents, which are miscible in both alcohol and paraffin, are used to remove the alcohol prior to infiltration of the specimen with melted paraffin. Xylene is most commonly used solvent in this and most other laboratories. Benzene is also used as a clearing agent 4th Step – Immersion in paraffin wax. 5th Step – Blocking and Sectioning of specimen. 6th Step – Staining of sections. Specimen is stained to permit Examination by dissolving the paraffin and (1)rehydrated through a descending series of alcohol to water. Slides are (2)stained with Hematoxylin and counterstained with Eosin, (3)dehydrated through an ascending series of alcohol, passed through an organic solvent and covered with a coverslip to obtain a permanent section.
59. Tissue Preparation for Electron Microscopy 1. Sections of Embedded MaterialBiological material contains large quantities of water. Since the TEM works in vacuum, the water must be removed. To avoid disruption as a result of the loss of water, you preserve the tissue with different fixatives. These cross-link molecules with each other and trap them together as stable structures. The tissue is then dehydrated in alcohol or acetone. After that, your specimen can be embedded in plastic that polymerize into a solid hard plastic block. The block is cut into thin sections by a diamond knife in an instrument called ultramicrotome. Each section is only 50-100 nm thick. The thin sections of your sample is placed on a copper grid and stained with heavy metals. The slice of tissue can now be studied under the electron beam.
60. LEARNING OBJECTIVE 6 DISCUSS THE NEED FOR INTRA-CELLULAR COMPARTMENTMENTALISATION AND THE BASIC PRINCIPLES OF INTRACELLULAR METABOLISM
61. Intracellular Compartmentalisation The major intracellular compartments of an animal cell are the: Cytosol Endoplasmic reticulum Golgi apparatus, Nucleus Mitochondion Endosome Lysosome Peroxisome
62. The precursors of the first eucaryotic cells were simple organisms that resembled bacteria. These had a plasma membrane but no internal membranes, therefore the plasma membrane in such cells therefore provides all membrane-dependent functions the pumping of ions ATP synthesis protein secretion Lipid synthesis. Eucaryotic cells today are much larger than those cells were ( 10–30 times greater in linear dimension &1000–10,000 times greater in volume)
63. Because of this increase in size, the eucaryotic cell has a much smaller ratio of surface area to volume. As a result, the plasma membrane is too small to sustain the many vital functions for which membranes are required. From these observations, the internal membrane compartments which eucaryotic cells contain may be viewed as an evolutionary adaptation, in order to carry out its vital functions Additionally, intracellular compartmentalisation has allowed for the development of specialised membrane function and organelles.
65. LEARNING OBJECTIVE 7 DISCUSS VIEWING WHOLE, LIVING CELLS vs. DEAD “MASHED UP” CELLS.
66. Advantages of viewing “Whole,” Living Cells Able to observe how certain structures/organelles function. E.gmicrovilli, golgi vesicles Preserves life.
67. Disadvantages of viewing “Whole,” Living Cells Difficult to observe all cells efficiently while they are alive. In only viewing the surface of the cell, it is impossible to develop a full understanding of its complete workings
68. Advantages of Viewing “Mashed Up,” Dead Cells Allows for better viewing methods (e.g. electron microscopy which requires the cell be dead) “Mashing up” the cells, allows biochemists to learn what compounds the cells and their components are made up of. Biochemists can then apply what they know about the behaviour of said compounds to determine the function(s) of the subject matter.
69. Disadvantages of viewing “Mashed Up,” Dead Cells The specimen being studied dies. Researchers are unable to view the actions of the specimen being studied.