Enzymes and Digestion F4 Flashcards
What are enzymes?
A biological catalyst that speeds up reactions without being used in the reaction itself
What are enzymes made of?
Protein
What is enzyme specificity?
Each enzyme is specific in that it will only work on one type of substrate
What is the optimum of an enzyme?
When the enzyme is at its highest rate of activity
How does low temperature affect enzyme activity?
Enzyme and substrates have low kinetic energy so there are fewer collisions and therefore enzyme activity is low
How does high temperature affect enzyme activity?
At temperatures above the optimum enzymes begin to denature. The increase in temperature changes the shape of the active site, no longer fitting the substrate and so rate of activity decreases.
How does pH affect enzyme activity?
On either side of the optimum pH they work less well because the incorrect pH changes the shape of the enzyme’s active site
How does increasing enzyme concentration affect enzyme activity?
More active sites become available for substrates to fit into, increasing the activity
How does higher enzyme concentration affect enzyme activity?
Rate of activity levels off as enzyme concentration increases because the number of substrate molecules becomes limiting and there are not enough to react with the extra enzymes
What are inhibitors?
Molecules/Substances which fit loosely into an enzyme’s active site, stopping the substrate from fitting
How do inhibitors affect enzyme activity?
These molecules reduce normal enzyme activity
What is digestion?
Breaking down of large, insoluble food molecules into small, soluble molecules that can be absorbed
What is absorption?
The process in which small, soluble food molecules are transferred from the gut to the blood system
Substrate and product of CARBOHYDRASE
Starch => glucose
Substrate and product of PROTEASE
Protein => amino acids
Substrate and product of LIPASE
Fat => glycerol, fatty acids
What are the functions of the lacteal?
Absorbs glycerol and fatty acids, returning them to the blood later
What are the functions of the capillary network?
- absorbs amino acids and glucose
- provides excellent blood supply (maintains low concentration gradient)
What are the functions of the thin and permeable surface lining?
- consists of single layer of epithelium cells creating short diffusion distance
What does it mean to be thermostable?
Can work effectively at a wide range of temperatures.
What does it mean to DESCRIBE a graph?
‘Say what you see’ - discuss trend of the graph using data
What does it mean to EXPLAIN a graph?
‘Science bit’ - why it’s taking place
How does increasing temperature affect enzyme activity?
It increases the kinetic energy, the number of collisions and therefore the rate of activity also increases
What is the effect of pre-digesting food for babies?
It increase the surface area of the food, making it easier for enzymes to act on.
What advantage does the shape of a villus provide?
Its finger-like shape increases the surface area
