Chapter 4 - enzymes Flashcards
1
Q
why are enzymes important?
A
- they catalyse chemical reaction so that they can happen very fast
2
Q
what is the structure of enzymes?
A
- biological catalysts
- globular proteins
- interact with substrate molecules
3
Q
what is the role of enzymes in reactions?
A
- catalyse anabolic (building up) reactions
- catalyse catabolic (breaking down) reactions
4
Q
what is the mechanism of enzyme action?
A
- specificity of the enzyme=each enzyme catalyses one biochemical reaction
- activation energy=the amount of energy needed for a reaction to start
- enzymes help molecules collide successfully - reduces activation energy required
5
Q
what is the induced fit hypotheses?
A
- the active site of the membrane changes shape slightly as the substrate enters
6
Q
what are intracellular enzymes?
A
- enzymes that act within cells
- e.g, catalase=ensures hydrogen peroxide is broken down quickly to prevent accumulation
7
Q
what are extracellular enzymes?
A
- work outside the cells that made them
- examples in digestion=amylase and trypsin
8
Q
how is starch digested?
A
- in two steps
1) starch polymers partially broken down into starch (disaccharide) by amylase (produced in salivary glands and pancreas)
2) maltose is broken down into glucose (monosaccharide) by maltase (present in small intestine)
9
Q
how are proteins digested?
A
- trypsin (produced in pancreas) catalyses digestion of proteins into peptides then amino acids
- amino acids are absorbed by cell lining in digestive system and absorbed into bloodstream
