Chapter 2 Cellular Structure & Physiology.pdf

Essentials of Human Anatomy & Physiology
For. Romualdo B. De Guzman, Jr.,
MSA, MBio
Associate Professor II
Chapter 2
Plant Cell and Cell
Physiology

Cell Dicovery
Robert Brown (1831) a British botanist.
❑identify the central part of the cell and called it the
nucleus and also described the cytoplasm as the
grayish fluid that suspend inside the cell.
Dujardin (1835) a French biologist.
❑observed that cells are composed of fluid filled with
thick, jelly-like fluids the surround the cells and
called them protoplasm.

Cell Dicovery
Robert Hooked (1665)a British scientist.
❑He discovered tiny cubical shape mass from the
slice cork on his self-constructed microscope and
named it “cells”.
Anton Van Leeuwenhoek (1674) Dutch scientist.
❑made discoveries concerning protozoa, red blood
cells, capillary systems and the life cycle of the
insects out of his modified compound microscope.

Cell Dicovery
Matthias Schleiden (1838) and Theodore Schwann
(1839) a botanist and zoologist.
❑concluded that plants and animals are composed of
cells and developed the theory about cell.
Rudolf Vichow1858 by a German pathologist.
❑theory was basis of statement that, “all cells must
come only from pre-existing cells which become the
interest of other scientific studies about cell.”

Cell Dicovery
German Engineer Max Knoll and Ernst Ruska in 1932.
❑ built and developed the first transmission electron
microscope that gives more detail in discovering the
different organelles inside the cell.
James Watson, American biochemist and Francis Crick,
British biophysicist in 1953.
❑ significant discovery about cells is the DNA structure.
❑ gave way to the science of molecular biology and it is used
in advance study like, genetics, molecular systematic,
organic chemistry, biochemistry and others.

Cell Defined as:
❑it is the basic fundamental unit of all living
organisms capable of duplication and
multiplication.

Types of Cells
1. Prokaryotic cells (Greek pro, before, and
Karyon, nucleus).
❑type of cell has no nucleus common characteristic
of bacteria with a size ranging from (1 to 10
microns).
❑outer part is composed of cell wall & plasma
membrane.
❑The cytoplasm contains ribosome, thylakoids and
innumerable enzyme.
❑nucleoid contain single chromosome consist of the
DNA.

Types of Cells
2. Eukaryotic cells (Greek eu, true and karyon,nucleus).
❑a true nucleus common characteristic of protists
(unicellular cell), fungi, plants andanimals.
❑consist plasma membrane, cytoplasm and a central
nucleus.
❑nucleus is membrane bounded containing multiple
chromatin and DNA inside it.
❑plasma membrane made of phospholipids bi-layer .
❑Cytoplasm contains organelles for control, synthesisand
metabolic processes inside the cell.

Cells and Tissues – C, O, H, N
• Carry out all chemical activities needed
to sustain life.
• Cells are the building blocks of all living
things
• Tissues are groups of cells that are
similar in structure and function
• Structure reflects function
Slide 3.1
Copyright © 2003 Pearson Education, Inc. publishingas Benjamin Cummings

Anatomy of the Generalized Cell
• Cells are not all the same
• All cells share general structures
• Cells are organized into three main
regions
•Nucleus
•Cytoplasm
•Plasma membrane
Figure 3.1a
Slide 3.2

The Nucleus
• Control center
of the cell
• Contains genetic
material (DNA)
• Three regions
• Nuclear
membrane
• Nucleolus
• Chromatin Figure 3.1b
Slide 3.3

Nuclear Membrane – double
membrane or envelope
• Barrier of nucleus
• Consists of a double phospholipid
membrane
• Contain nuclear pores that allow for
exchange of material with the rest of the
cell – selectively permeable
Slide 3.4

Nucleoli
• Nucleus contains one or more nucleoli
• Sites of ribosome production
• Ribosomes then migrate to the
cytoplasm through nuclear pores
Slide 3.5

Chromatin (when not dividing)
• Composed of DNA and protein
• Scattered throughout the nucleus
• Chromatin condenses to form
chromosomes when the cell divides
Slide 3.6

Plasma Membrane
Slide 3.7a
• Barrier for cell contents
• Double phospholipid layer (fat – water)
•Hydrophilic heads
•Hydrophobic tails
• Other materials in plasma membrane
•Protein
•Cholesterol
•Glycoproteins

Plasma Membrane
3.7b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide
Figure 3.2

Cytoplasm
Slide 3.9
• Material outside the nucleus and inside
the plasma membrane
•Cytosol
•Fluid that suspends other elements
•Organelles
•Metabolic machinery of the cell
•Inclusions
•Non-functioning units – fat, pigments…..

Cytoplasmic Organelles
10
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3.
Figure 3.4

• Ribosomes
•Made of protein and RNA
•Sites of protein synthesis
•Found at two locations
•Free in the cytoplasm
•Attached to rough endoplasmic reticulum
Slide 3.11

• Endoplasmic reticulum (ER)
• Fluid-filled tubules for carrying substances
• Two types of ER
• Rough Endoplasmic Reticulum
• Studded with ribosomes
• Site where building materials of cellular
membrane are formed
• Smooth Endoplasmic Reticulum
• Functions in cholesterol synthesis and
breakdown, fat metabolism, and detoxification
of drugs
Slide 3.12

Slide 3.13a
• Golgi apparatus
•Modifies and packages proteins

Slide 3.13b
Figure 3.5

Slide 3.15
• Mitochondria
• “Powerhouses” of the cell
• Change shape continuously
• Carry out reactions where oxygen is used
to break down food
• Provides ATP for cellular energy

Slide 3.16a
• Cytoskeleton
•Network of protein structures that extend
throughout the cytoplasm
•Provides the cell with an internal framework

Slide 3.16b
• Cytoskeleton
•Three different types
• Microfilaments
• Intermediate
filaments
• Microtubules
Figure 3.6

• Centrioles
•Rod-shaped bodies made of microtubules
•Direct formation of mitotic spindle during
cell division
Slide 3.17

Cellular Physiology:
Membrane Transport
• Membrane Transport – movement of
substance into and out of the cell
• Transport is by two basic methods
•Passive transport
•No energy is required
•Active transport
•The cell must provide metabolic energy
Slide 3.20

Selective Permeability
• The plasma membrane allows some
materials to pass while excluding others
• This permeability includes movement
into and out of the cell
Slide 3.22

Passive Transport Processes
• Diffusion
• Particles tend to distribute themselves evenly
within a solution
• Movement is
from high
concentration
to low
concentration,
or down a
concentration
gradient
Figure 3.8
Slide 3.23

Slide 3.24b
• Types of diffusion
•Osmosis – simple diffusion of water
•Highly polar water easily crosses the
plasma membrane
•Facilitated diffusion (glucose)
•Substances require a protein carrier for
passive transport

Diffusion through the Plasma
Membrane
Figure 3.9
Slide 3.25

• Filtration
•Water and solutes are forced through a
membrane by fluid, or hydrostatic pressure
•A pressure gradient must exist
•Solute-containing fluid is pushed from a
high pressure area to a lower pressure
area
Slide 3.26

Active Transport Processes (ATP)
• Transport substances that are unable to pass
by diffusion
• They may be too large
• They may not be able to dissolve in the fat core
of the membrane
• They may have to move against a concentration
gradient
• Two common forms of active transport
• Solute pumping
• Bulk transport
Slide 3.27

Active Transport Processes
Slide 3.28a
• Solute pumping
•Amino acids, some sugars and ions are
transported by solute pumps
•ATP energizes protein carriers, and in most
cases, moves substances against
concentration gradients

Slide 3.28b
Figure 3.10

Slide 3.29a
• Bulk transport
•Exocytosis
• Moves materials out of the cell
• Material is carried in a membranous vesicle
• Vesicle migrates to plasma membrane
• Vesicle combines with plasma membrane
• Material is emptied to the outside

Slide 3.29b
Figure 3.11

Slide 3.30a
• Bulk transport
•Endocytosis
•Extracellular substances are engulfed by
being enclosed in a membranous
vescicle
•Types of endocytosis
•Phagocytosis – cell eating
•Pinocytosis – cell drinking

Cell Life Cycle
• Cells have two major periods
•Interphase
•Cell grows
•Cell carries on metabolic processes
•Cell division
•Cell replicates itself
•Function is to produce more cells for
growth and repair processes
Slide 3.31

DNA Replication
• Genetic material
duplicated and
readies a cell for
division into two cells
• Occurs toward the
end of interphase
• DNA uncoils and
each side serves
as a template
Slide 3.32
Figure 3.13

Events of Cell Division
• Mitosis
•Division of the nucleus
•Results in the formation of two daughter
nuclei
• Cytokinesis
•Division of the cytoplasm
•Begins when mitosis is near completion
•Results in the formation of two daughter
cells
Slide 3.33

Stages of Mitosis
Slide 3.36a
Figure 3.14; 1

Stages of Mitosis
Slide 3.36b
Figure 3.14; 2

Protein Synthesis
• Gene – DNA segment that carries a
blueprint for building one protein
• Proteins have many functions
•Building materials for cells
•Act as enzymes (biological catalysts)
• RNA is essential for protein synthesis
Slide 3.37

Role of RNA
• Transfer RNA(tRNA)
•Transfers appropriate amino acids to the
ribosome for building the protein
• Ribosomal RNA(rRNA)
•Helps form the ribosomes where proteins
are built
• Messenger RNA
•Carries the instructions for building a
protein from the nucleus to the ribosome
Slide 3.38

Transcription and Translation
• Transcription
•Transfer of information from DNA’s base
sequence to the complimentary base
sequence of mRNA
• Translation
•Base sequence of nucleic acid is translated
to an amino acid sequence
•Amino acids are the building blocks of
proteins
Slide 3.39

Chapter 2 Cellular Structure & Physiology.pdf

Chapter 2 Cellular Structure & Physiology.pdf

More Related Content

Similar to Chapter 2 Cellular Structure & Physiology.pdf

Recently uploaded

Chapter 2 Cellular Structure & Physiology.pdf