Download Biochemistry

Biochemistry
Carbon Compounds
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Why carbon?
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Has four valence
electrons
These can join with four
more electrons from
other atoms
Can bond with other
carbon atoms
Macromolecules
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Giant molecules
Formed by polymerization – large molecules
built by joining smaller ones together
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Monomers: small units
Polymers: 3 or more small units together
Types of Macromolecules
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Four groups of organic compounds
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Carbohydrates
Lipids
Nucleic acids
Proteins
Carbohydrates
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Made of carbon, hydrogen, oxygen
1:2:1 ratio of above elements
Living things use carbohydrates as main
source of energy
Carbs, cont.
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Simple sugars = MONOSACCHARIDES
Glucose, galactose (milk), fructose (fruits)
Large molecules = POLYSACCHARIDES
Glycogen = animal starch, in liver
Cellulose = plant starch
Lipids
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Made mostly of carbon and hydrogen
Fats, oils and waxes
Used to store energy
2 parts: glycerol and fatty acids
2 main types:
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Saturated: maximum number of hydrogen atoms
Unsaturated: at least 1 carbon to carbon bond
Polyunsaturated: more than one carbon to carbon bond
Nucleic Acids
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Macromolecules containing H, O, N, C, P
Store and transmit hereditary information
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DNA – deoxyribonucleic acid; sugar is deoxyribose
RNA – ribonucleic acid; sugar is ribose
Monomers called nucleotides
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3 parts:
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5-carbon sugar
Phosphate group
Nitrogenous base
Proteins
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Macromolecules contain C, H, O, N
Polymers made of monomers called
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Amino Acids (there are 20 of them)
Various jobs:
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Control rate of reactions in cells
Regulate cell processes
Used to form bone and muscle
Transport substances in and out of cells
Help fight disease
Proteins, cont.
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Four levels of organization
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1. sequence of amino acids in a chain
2. can be twisted or folded
3. chain itself is folded
4. can have more than one chain, folded around
each other
Chemical
Reactions
Chemical Reactions
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Process that changes one
set of chemicals into another
set of chemicals
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Rust
Hydrogen and oxygen
Reactants: elements or
compounds that enter into a
chemical reaction
Products: elements or
compounds produced by a
chemical reaction
Energy in Reactions
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Energy is either released or absorbed when
chemical bonds are made or broken
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If release energy, occur spontaneously
If absorb energy, need a source of energy
In living things, need to carry out reactions
that require energy
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Plants – sunlight
Animals -- food
Enzymes
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Some chemical reactions in living things are
too slow, or too fast
Cells make catalysts
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Speeds up rate of reaction
If energy too high then lowers that energy
Enzymes = proteins that act as biological
catalysts
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Lowers the energy needed for a reaction to take
place
Enzymes, cont.
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They are very specific; only works on one
chemical reaction
They get their name from the reaction
Enzymes in action
Enzyme Action
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Enzyme-Substrate Complex
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Enzymes provide a site
where reactants can be
brought together
Reduces the amount of
energy needed for reaction
Substrate = what is broken
down
Active site = where
substrate binds on the
enzyme
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Lock-and-key model
Enzymes, cont.
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What affects enzyme activity
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pH
Temperature