4. Proteins Flashcards
What are proteins made of
Many amino acids joined together in a unique order
How are proteins structured
Amino acids are joined in a long chain, which is then folded in various ways to make unique shapes
Why does each protein have a unique shape
Because the shape is relative to the function
What are the functions of a protein
Enzyme - biological catalyst
Hormone - chemical messenger, travels in blood, target tissues
Antibody - Locks onto pathogens, destroying them,
‘Y’ shaped
Receptor - found in the cell membrane, locks onto molecules, to trigger a specific change in cell
Structural - body tissues, tough and strong
What determines an enzymes function
Their particular shape
Where are enzymes found
In all living cells
What do enzymes do
They:
Lower activation energy required to start reactions
Speed up chemical reactions
Remain unchanged after reactions
Why are enzymes required
Organisms can only exist at relatively low temperatures, so could not stand the high temperatures required for rapid reactions
Enzymes allow these reactions to occur at the low temperatures needed to sustain life
What are the two types of reactions an enzyme can carry out
Catabolic - breaks down molecules (degrading)
Anabolic - builds up molecules (synthesis)
What do enzymes react with and produce (general equation)
Substrate > Substrate-enzyme complex > Product
What is the name of the surface of an enzyme where substrates lock on
The active site
How is the shape of the active site determined
By the folding of the amino acids
What relevance is there between the shape of a substrate and the active site of an enzyme, and why is this
They are complementary shapes, because enzymes are specific to one reaction, which means other substrates will not be effected
Which analogy best describes the relationship between a substrate and an enzyme
Lock and key
What is the definition of an optimum condition
Ideal conditions, suitable temperature and pH,
Where an enzyme is most active
