Biochemistry
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Transcript Biochemistry
Biochemistry
Carbon Compounds
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
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
Four groups of organic compounds
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Carbohydrates
Lipids
Nucleic acids
Proteins
Carbohydrates
Made of carbon, hydrogen, oxygen
1:2:1 ratio of above elements
Living things use carbohydrates as main
source of energy
Carbs, cont.
Simple sugars = MONOSACCHARIDES
Glucose, galactose (milk), fructose (fruits)
Large molecules = POLYSACCHARIDES
Glycogen = animal starch, in liver
Cellulose = plant starch
Lipids
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
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:
5-carbon sugar
Phosphate group
Nitrogenous base
Proteins
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.
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
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
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
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.
They are very specific; only works on one
chemical reaction
They get their name from the reaction
Enzymes in action
Enzyme Action
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
Lock-and-key model
Enzymes, cont.
What affects enzyme activity
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pH
Temperature