Biology Term 3 Flashcards
1
Q
why are enzymes important
A
- reactions can be slow without
- reaction can work in low temperature
- reduces activation energy
2
Q
What are the factors affecting enxyme activity?
A
- Temperature
- if temp is 0, enzyme activity also 0
- if temp increase, enzyme activity also increase
- if temp go above limit:
- denatured
- enz activity = 0
- shape of active site not complimentary to shape of substrate
- pH
- if pH over/less than limit, denatured
- Enzyme and substance concentration
3
Q
What is digestion? How is it different from absorption?
A
- digestion: the breakdown of large insoluble molecules to small soluble molecules permanently without chemi reaction
- absorption: food molecules going through wall of intestine to the blood.
4
Q
What is mechanical digestion?
A
- contraction/relaxation of muscles to break down food and move it through digestive system.
5
Q
What is chemical digestion?
A
- when acids and enzymes break down the food into nutrients
6
Q
What is the difference between ingestion and egestion?
A
- ingestion: the take in of substance to body from mouth
- egestion: the take out of non digested food through the anus
7
Q
Name main parts of the alimentary canal:
A
- mouth
- oesophagus
- stomach
- small intestine: duodenum & ilieum
- large intestine: colon
- rectum
- anus
8
Q
What are the functions of the mouth?
A
- chews the food up
- mixes with saliva to help dissolve
9
Q
Functions of the oesophagus:
A
- takes food down to stomach
10
Q
Functions of stomach:
A
- muscle contract/relax to churn food
- stomach wall have goblet cell - have protese enz making HCL
- Pepsin secreated to breakdown polypeptides
- Works well in acidic condition - kill bacteria
11
Q
Function of small intestine:
A
- narrow - 5m long
- pancreatic juice secreated from pancreas through pancreatic duct
- fluid contains enzyme: amylase, protese, lipase (typsin)
12
Q
Function of Bile (s.i):
A
- yellowish green alkaline - neutralises acid from stomach
- made in liver - stored in gall bladder
- no enzyme but help digest fats
- emulsification: 2 substance combined that don’t mix easily tgth usually
- easy for lipase to digest fat
- emulsification: 2 substance combined that don’t mix easily tgth usually
13
Q
Function of villi (s.i):
A
- secreates enzymes for digestion
- maltase
- sucrase
- peptisade
- lipase
- lactase
- has villius covered with cell
- Contain blood capillaries - A.A, monosacharides, minerals etc taken to liver then body
- one cell thick - fast diffusion
- goblet cells secrete mucus to protect from protese, lipase, physiscal damage, acid from stomach
14
Q
Function of large intestine:
A
- to absorb water and nutrients
* mostly water absorbed in colon
15
Q
What is the purpose of the circulatory system?
A
- to transport oxygen and nutrients to body