chemistry atoms are the basic units of matter cells are the basic units of life cells are made of...
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Chemistry• Atoms are the basic units of matter• Cells are the basic units of life
• Cells are made of matter, especially organic matter (contains carbon atoms)
• The principal categories of organic matter are:– Carbohydrates– Lipids– Proteins– Nucleic acids
pH• pH - a measure of the amount of
hydrogen ions in a solution. Concentration of hydrogen [H+].
• The relationship between [H+] and pH is: pH=-log [H+].
• pH varies between 0 and 14, neutral pH =7= pH of water.
• The higher the acidity, the higher the concentration of hydrogen ions is. For every unit of pH, the hydrogen concentration in the solution multiplies by
• This concept of acidity is very important for life
Organic compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
Carbohydrates: C6 or C5 ring
* C6 ring: common carbohydrates:
- 1 ring: glucose, fructose, galactose
- 2 rings: sucrose, lactose, maltose
- Many rings: glycogen, starch
- Role: Short term energy storage
Carbohydrates: C6 or C5 ring
• C5 ring: special role
• In ATP, nucleic acids
Organic compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
Lipids
• Formed by a glycerol backbone and attached fatty-acids
• Fatty-acids: a string of carbons with hydrogen atoms
• Molecules hydrophobic and rich in energy long term energy storage
Figure 2-8 (3 of 6)
Figure 2-8 (2 of 6)
Phospholipids
• One fatty-acid is replaced by a phosphoric group property of the molecule changes amphipatic molecules (like both water and lipids)
Figure 3-15 - Overview
Lipid: Cholesterol
• Component of cell membrane
• Base for steroid hormones
Organic compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
Proteins
• Two basic roles:- Structural: building block of the cell (collagen, elastin..)
- Enzymatic: control metabolism (enzymes)
Proteins: Primary structure
• The primary structure of a proteins is its string of amino acids.
• These a.a. are covalently (strongly) attached
• There are 20 different amino acids that can potentially be found in the proteins
• The order of a.a. varies different sequences
Secondary structure of a protein
• Folding of the a.a. chain - fold as a alpha helix
- or a beta sheet
Tertiary structure of a protein
• Folding of the chain due to hydrogen bonds formed by the various amino acids
** This folding gives the protein its shape the shape of a protein gives it its function
Figure 2-16
Figure 2-9 - Overview (1 of 7)
Figure 2-9 (2 of 7)
So what happens when the pH in the cell changes?
So what happens when the pH in the cell changes?
• The protein changes shape loose its function denaturation
Organic compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
Nucleic acid• DNA• RNA• ATP
• Formed by a C5 carbohydrate + phosphate + a base
• Bases: adenine, cytosine, thymine, guanine and uracil
Figure 2-12 - Overview