Comparison of Abilities Human eye Light microscope Transmission Electron Microscope
Levels of Organisation Living Organisms systems organs tissues cells Biomolecules Organic carbohydrates proteins lipids nu...
Levels of Organisation Biomolecules Organic carbohydrates proteins lipids nucleic acids Inorganic Ions Water (inorganic) s...
Cells!
The nature of the cell Intracellular aqueous  environment Extracellular aqueous  environment Cell boundary or  plasma memb...
What all cells need to do Make specific  Biomacromolecules Control and regulate chemical Reactions Produce energy to drive...
Cell structure needs to meet the needs of molecules <ul><li>The processes within a cell are due to molecules interacting w...
Why size and shape matters <ul><li>Cells need to maximise their surface area to ensure the rapid movement of of molecules....
So how do organisms deal with having cells with an insufficient SA:V to facilitate the transport of molecules? <ul><li>ORG...
Animal Cells
Plant Cells
 
The functions of organelles: <ul><li>Movement of substances across the plasma membrane </li></ul><ul><li>The protein secre...
 
WATER
A little chemistry … Covalent bonding involves atoms joining to form molecules In order to form a stable molecule, each at...
 
Oxygen has an atomic number of 8
 
Hydrogen has an atomic number of 1
A little chemistry … …  and a hydrogen atom contains 1 proton and 1 electron So an oxygen atom contains 8 protons and 8 el...
A little chemistry … When oxygen and hydrogen bond, the hydrogen is stable, it has a full outer shell …  but the oxygen is...
A little chemistry … This allows an additional hydrogen atom to bond with the oxygen …  thus creating a stable molecule
A little chemistry … Thus we achieve the structure of a water molecule: One oxygen atom bonded to two hydrogen atoms
How water interacts with other substances <ul><li>If a substance is composed of charged atoms, these will be attracted to ...
pH <ul><li>pH is simply a measure of the number of hydrogen ions vs the number of hydrogen ions in a solution. </li></ul><...
Water molecules are cohesive -> they form  hydrogen bonds Substances that dissolve in water are called  hydrophilic  or  p...
Monomers: Polymers: Sugars Carbohydrates (Polysaccharides) Amino Acids Proteins Fatty acids & glycerol Lipids Nucleotides ...
From molecules to biomacromolecules <ul><li>Biomacromolecules are giant molecules. They play essential roles in both the s...
Glucose, Fructose Sucrose, Lactose Starch, Glycogen & Cellulose
hexose shape pentose shape Mostly ends in  –ose C, H, O => organic Condensation reaction
<ul><li>Monomers are flanked by a hydroxide and a hydroxyl group </li></ul><ul><li>When the reaction is facilitated by an ...
<ul><li>The correctly aligned interaction of the hydroxide group of one monomer with the hydroxyl group of another  will c...
<ul><li>The end result is a larger molecule, with its two monomers joined by an oxygen bridge </li></ul>The Condensation R...
<ul><li>This is simply the opposite to a condensation reaction </li></ul><ul><li>When an enzyme exerts pressure on the lar...
<ul><li>One of the hydrogen atoms attaches to the oxygen, whilst the other oxygen and hydrogen attach to the other monomer...
 
Energy storage <ul><li>In Animals </li></ul><ul><ul><ul><li>Food broken down to glucose </li></ul></ul></ul><ul><ul><ul><l...
Lipids <ul><li>Comprised of two types of subunits: </li></ul><ul><ul><ul><li>Fatty acids </li></ul></ul></ul><ul><ul><ul><...
 
Triglycerides Phospholipids
How the monomers interact <ul><li>The reason that lipids are not polymers is that there is only one gycerol subunit with t...
Other than phospholipids, which contain P, most others will only contain C, H & O
DNA: deoxyribonucleic acid RNA: ribonucleic acid
Nucleic acids contain C, H & O in addition to N & P SUGAR PHOSPHATE
DNA: Adenine (A) Thymine (T) Cytosine (C) Guanine (G) RNA: Adenine (A) Uracil (U) Cytosine (C) Guanine (G)
Differences between DNA & RNA DNA RNA A, C, G, T A, C, G, U Paired strands Single strand H +  at 2’ OH -  at 2’
Summary of animation <ul><li>mRNA copy of gene on DNA made in nucleus </li></ul><ul><li>mRNA swims out to ribosome (made f...
 
3 groups: Amino group, Carboxyl group & R-group When joined together they form  peptide bonds Aside from the C, H, O & N i...
Protein structure <ul><li>Primary structure </li></ul><ul><ul><ul><li>The linear sequence of amino acids </li></ul></ul></...
Primary structure: Secondary structure:
Tertiary structure: Quaternary structure:
Active vs inactive proteins <ul><li>Not all proteins are produced in an active form </li></ul><ul><li>Often they will need...
 
Biomacromolecule Type of bonding Carbohydrates Glycosidic bond Lipids Ester bond Nucleic acids Phosphodiester bond Protein...
 
 
Upcoming SlideShare
Loading in …5
×

1 - The Chemical Nature of Cells

3,645 views

Published on

Published in: Education, Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
3,645
On SlideShare
0
From Embeds
0
Number of Embeds
1,932
Actions
Shares
0
Downloads
34
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

1 - The Chemical Nature of Cells

  1. 1. Comparison of Abilities Human eye Light microscope Transmission Electron Microscope
  2. 2. Levels of Organisation Living Organisms systems organs tissues cells Biomolecules Organic carbohydrates proteins lipids nucleic acids Inorganic Ions Water (inorganic)
  3. 3. Levels of Organisation Biomolecules Organic carbohydrates proteins lipids nucleic acids Inorganic Ions Water (inorganic) simple sugars amino acids fatty acids nucleotides glycerol
  4. 4. Cells!
  5. 5. The nature of the cell Intracellular aqueous environment Extracellular aqueous environment Cell boundary or plasma membrane <ul><li>Insoluble </li></ul><ul><li>Semi-permeable </li></ul>
  6. 6. What all cells need to do Make specific Biomacromolecules Control and regulate chemical Reactions Produce energy to drive Chemical reactions Take in small molecules Produce useful products for export from the cell Receive and respond to chemical signals Remove waste products Grow, reproduce and pass on genetic information to the next generation of cells
  7. 7. Cell structure needs to meet the needs of molecules <ul><li>The processes within a cell are due to molecules interacting with each other </li></ul><ul><li>Molecules need to move into and around the cell at a certain rate to reach sites of specific activity </li></ul><ul><li>Molecules need to be in adequate concentrations if chemical reactions are going to occur at the right rate </li></ul><ul><li>Cell structure needs to facillitate the movement of molecules and maintain them in adequate concentrations so reactions can occur to maintain cell functioning </li></ul>
  8. 8. Why size and shape matters <ul><li>Cells need to maximise their surface area to ensure the rapid movement of of molecules. This becomes a problem as the volume of the cell increases. Size does matter! </li></ul>A B C Shape A B C L x W x H 1x1x1 10x10x 10 10x100x1 Surface Area (6a 2 ) 6 600 2200 Volume (a 3 ) 1 1000 1000 SA:V (SA/V) 6 0.6 2.2
  9. 9. So how do organisms deal with having cells with an insufficient SA:V to facilitate the transport of molecules? <ul><li>ORGANELLES! </li></ul><ul><li>Each of the intracellular organelles will be studied this semester, but the emphasis will be on their various functions, and how they compensate for the relatively large volumes of eukaryotic cells </li></ul><ul><li>Prokaryotic cells being smaller, do not have this necessity </li></ul>
  10. 10. Animal Cells
  11. 11. Plant Cells
  12. 13. The functions of organelles: <ul><li>Movement of substances across the plasma membrane </li></ul><ul><li>The protein secretory pathway </li></ul><ul><li>Photosynthesis </li></ul><ul><li>Cellular respiration </li></ul><ul><li>The signal transduction pathway </li></ul><ul><li>Aspects of the immune response </li></ul><ul><li>Packaging and export of cellular products </li></ul>
  13. 15. WATER
  14. 16. A little chemistry … Covalent bonding involves atoms joining to form molecules In order to form a stable molecule, each atom must share sufficient electrons in order to result in a full outer shell If an atom only has one shell of electrons, 2 is sufficient to fill it The second shell and onwards all require a minimum of 8 electrons in order to achieve stability
  15. 18. Oxygen has an atomic number of 8
  16. 20. Hydrogen has an atomic number of 1
  17. 21. A little chemistry … … and a hydrogen atom contains 1 proton and 1 electron So an oxygen atom contains 8 protons and 8 electrons
  18. 22. A little chemistry … When oxygen and hydrogen bond, the hydrogen is stable, it has a full outer shell … but the oxygen is still left short one electron
  19. 23. A little chemistry … This allows an additional hydrogen atom to bond with the oxygen … thus creating a stable molecule
  20. 24. A little chemistry … Thus we achieve the structure of a water molecule: One oxygen atom bonded to two hydrogen atoms
  21. 25. How water interacts with other substances <ul><li>If a substance is composed of charged atoms, these will be attracted to the negatively charged oxygen atom or the positively charged hydrogen atoms. These are known as polar or hydrophyllic. </li></ul><ul><li>If a substance has no charge, then it will not be able to interact with the water molecules. These are known as non-polar or hydrophobic. </li></ul>
  22. 26. pH <ul><li>pH is simply a measure of the number of hydrogen ions vs the number of hydrogen ions in a solution. </li></ul><ul><li>More H + = lower pH (0-6) = acidic </li></ul><ul><li>More OH - = higher pH (8-14) = basic </li></ul><ul><li>Equal H + and OH - = pH 7 = neutral </li></ul>
  23. 27. Water molecules are cohesive -> they form hydrogen bonds Substances that dissolve in water are called hydrophilic or polar Substances that are insoluble in water are called hydrophobic or non-polar
  24. 28. Monomers: Polymers: Sugars Carbohydrates (Polysaccharides) Amino Acids Proteins Fatty acids & glycerol Lipids Nucleotides Nucleic Acids
  25. 29. From molecules to biomacromolecules <ul><li>Biomacromolecules are giant molecules. They play essential roles in both the structure and function of cells </li></ul><ul><li>Cells import water, mineral ions and a host of small organic molecules like simple sugars, fatty acids and amino acids. </li></ul><ul><li>In contrast, cells can only acquire biomacromolecules by making them. They are made in a condensation reaction. </li></ul>
  26. 30. Glucose, Fructose Sucrose, Lactose Starch, Glycogen & Cellulose
  27. 31. hexose shape pentose shape Mostly ends in –ose C, H, O => organic Condensation reaction
  28. 32. <ul><li>Monomers are flanked by a hydroxide and a hydroxyl group </li></ul><ul><li>When the reaction is facilitated by an enzyme, they will come together in the correct alignment </li></ul>The Condensation Reaction Monomer H - O O - H Monomer H - O O - H
  29. 33. <ul><li>The correctly aligned interaction of the hydroxide group of one monomer with the hydroxyl group of another will cause the molecules to join, with water as a by-product </li></ul>The Condensation Reaction Monomer H - O O - H Monomer H - O O - H H 2 O
  30. 34. <ul><li>The end result is a larger molecule, with its two monomers joined by an oxygen bridge </li></ul>The Condensation Reaction Monomer H - O Monomer O O - H
  31. 35. <ul><li>This is simply the opposite to a condensation reaction </li></ul><ul><li>When an enzyme exerts pressure on the large molecule, the oxygen bridge is put under stress </li></ul><ul><li>This allows water to enter the bond </li></ul>Hydrolysis Monomer H - O Monomer O O - H H 2 O
  32. 36. <ul><li>One of the hydrogen atoms attaches to the oxygen, whilst the other oxygen and hydrogen attach to the other monomer in the form of a hydroxyl group. </li></ul><ul><li>The larger molecule has been divided in to two smaller subunits </li></ul>Hydrolysis Monomer H - O O - H Monomer H - O O - H H 2 O
  33. 38. Energy storage <ul><li>In Animals </li></ul><ul><ul><ul><li>Food broken down to glucose </li></ul></ul></ul><ul><ul><ul><li>Excess glucose stored as glycogen </li></ul></ul></ul><ul><ul><ul><li>Excess glycogen stored as fat </li></ul></ul></ul><ul><li>In Plants </li></ul><ul><ul><ul><li>Glucose produced via photosynthesis </li></ul></ul></ul><ul><ul><ul><li>Glucose combined with fructose to form sucrose </li></ul></ul></ul><ul><ul><ul><li>Sucrose transported to other parts of plant </li></ul></ul></ul><ul><ul><ul><li>Excess sucrose stored as starch </li></ul></ul></ul>
  34. 39. Lipids <ul><li>Comprised of two types of subunits: </li></ul><ul><ul><ul><li>Fatty acids </li></ul></ul></ul><ul><ul><ul><li>Glycerol </li></ul></ul></ul><ul><li>Molecules contain less water than carbohydrates, so can contain more energy </li></ul><ul><li>Thus lipids are a very important energy store for animals </li></ul>
  35. 41. Triglycerides Phospholipids
  36. 42. How the monomers interact <ul><li>The reason that lipids are not polymers is that there is only one gycerol subunit with three carbon atoms on to which the fatty acid chains can attach. </li></ul><ul><li>In triglycerides, one chain attaches to each of the three carbon atoms </li></ul><ul><li>In phospholipids, one of the carbons is taken up by a phosphate group, therefore there is only space for two fatty acid chains </li></ul>
  37. 43. Other than phospholipids, which contain P, most others will only contain C, H & O
  38. 44. DNA: deoxyribonucleic acid RNA: ribonucleic acid
  39. 45. Nucleic acids contain C, H & O in addition to N & P SUGAR PHOSPHATE
  40. 46. DNA: Adenine (A) Thymine (T) Cytosine (C) Guanine (G) RNA: Adenine (A) Uracil (U) Cytosine (C) Guanine (G)
  41. 47. Differences between DNA & RNA DNA RNA A, C, G, T A, C, G, U Paired strands Single strand H + at 2’ OH - at 2’
  42. 48. Summary of animation <ul><li>mRNA copy of gene on DNA made in nucleus </li></ul><ul><li>mRNA swims out to ribosome (made from rRNA) in cytoplasm </li></ul><ul><li>Ribosome reads code, for every 3 base pairs, 1 amino acid is added to the chain </li></ul><ul><li>Amino acids are brought to the ribosome by tRNA transfer molecules </li></ul><ul><li>Once process is complete, protein is released from the ribosome. </li></ul>
  43. 50. 3 groups: Amino group, Carboxyl group & R-group When joined together they form peptide bonds Aside from the C, H, O & N in the base molecule, the R group may also contain S & P
  44. 51. Protein structure <ul><li>Primary structure </li></ul><ul><ul><ul><li>The linear sequence of amino acids </li></ul></ul></ul><ul><li>Secondary structure </li></ul><ul><ul><ul><li>The type of peptide bond determines how sections of the protein fold – spiral helix / pleated sheet / random coils </li></ul></ul></ul><ul><ul><ul><li>Shape reinforced by additional H bonds </li></ul></ul></ul><ul><li>Tertiary structure </li></ul><ul><ul><ul><li>Eventual 3D shape formed by folding </li></ul></ul></ul><ul><ul><ul><li>Shape reinforced by additional H bonds </li></ul></ul></ul><ul><li>Quanternary structure </li></ul><ul><ul><ul><li>When a protein is formed by the interaction of 2 or more polypeptide chains </li></ul></ul></ul>
  45. 52. Primary structure: Secondary structure:
  46. 53. Tertiary structure: Quaternary structure:
  47. 54. Active vs inactive proteins <ul><li>Not all proteins are produced in an active form </li></ul><ul><li>Often they will need to be activated by a specific enzyme (also a protein) </li></ul><ul><li>In the case of the hormone insulin, it will only be activated when a disulphide bond is broken in the active site of the activating enzyme, thereby releasing one of its 3 polypeptide chains </li></ul><ul><li>So in our study of proteins, knowing the action of one is often not helpful, we need to know the make-up of the organism’s entire proteome. </li></ul>
  48. 56. Biomacromolecule Type of bonding Carbohydrates Glycosidic bond Lipids Ester bond Nucleic acids Phosphodiester bond Proteins Peptide bond

×