2.4 - adaptations for nutrition

Question 1

Autotroph

Answer 1

• An organism that creates complex molecules from simple molecules.

Question 2

2 types of autotrophs + definition

Answer 2

• photoautotroph = uses light energy
  -chemoautotroph = uses chemical energy

Question 3

What are the 2 main nutrition methods of Animals ?

Answer 3

• heterotrophic- consuming other organisms
  -holozoic - ingestion digestion, absorption and egestion

Question 4

What is saparotrophic nutrition ?

Answer 4

Nutrition from dead/decaying organisms
- |extracellular digestion

Question 5

Why is multicellular digestion less efficient than Animal digestion?

Answer 5

• ingestion + egestion occur at the same location
• Less enzymes
• Only 1 ph across whole system due to no different regions dor digestion

Question 6

4 functions of the gut

Answer 6

INGESTION
DIGESTION
ABSORPTION
EGESTION

Question 7

3 types of digestion

Answer 7

Mechanical digestion = teeth
chemical digestion (enzymes)
chemical digestion ( acid ph)

Question 8

Outline the structure of the gut X4

Answer 8

Serosa = reduce friction
longitudinal muscle + circular muscle = rhythmic contractions , L = relax C= contract
Submucosa = remove absorption products + nerve transmissions
Mucosa = produce mucus to lubricate the food moving through the gut.

Question 9

3 features of the buccal cavity

Answer 9

-HCO3 and co3 ions maintain ph7
-amalayse digests starch and glycogen into maltase
- mucus lubricates t he food for the passage down the oesophegus.

Question 10

Outline the features of the stomach

Answer 10

• 2 sphincteers which contract to keep food in the stomach for several hours.
  -stomach walls contract + mix with gastric juice.
  -extra layer of muscle for more powerful contractions

Question 11

What are the folds in the stomach wall called ?

Answer 11

Rugae

Question 12

ZYMOGEN - gastric juice

Answer 12

• Zymogen secretes pepsinogen which is activated by H+ ions into pespin which is an endopeptidase.

Question 13

Oxyntic cells - gastric juice

Answer 13

• oxyntic cells secrete HCL which lowers the Ph of the stomach
  -optimum ph for enzymes
  -kills majority of bacteria
  -base of gastric pit

Question 14

Goblet cells

Answer 14

• Goblet cells secrete mucus to lubricate food + protect stomach wall from enzymes
  -top of gastric pit

Question 15

Outline the components of bile
+purpose

Answer 15

• no enzymes
  -bile salts which have hydrophobic and hydrophillic parts
  -emulsifies lipids + lowers |SA
  -Alkaline + neutralises food coming from the stomach.

Question 16

Name the 4 enzymes in pancreatic juice

Answer 16

• Trypsinogen
  -Endopeptidase
  -Amalayse
  -Lipase

Question 17

Function of trypsinogen

Answer 17

trypsinogen is an inactive enzyme that is converted into trypsin - the endopeptidase by enterokinase .

Question 18

Endopeptidase

Answer 18

Hydrolyses polyep[eptides into peptides

Question 19

Role of NaCO3 in pancreatic juice

Answer 19

-neutralise acidic food from the stomach

Question 20

What is the Crypt of Lieberkuhn ?

Answer 20

-contain brunners gland which produce mucus to lubricate and neutralise food from stomach.
- On the small intestine wall

Question 21

4 Adaptation of the small intestestine

Answer 21

• contain villi + microvilli = increase SA
• capillary= maintian conc gradient
• Lacteal = absorb lipids
• epithelium = short diffusion

Question 22

Define a Ruminant

Answer 22

• Group of herbivores possessing a stomach that is divided into 4 chambers.

Question 23

Where is the Rumen and what is its function

Answer 23

In the gut of herbivores, where mutualistic microbes digest complex polysaccharides

Question 24

Describe the 7 steps of cellulose digestion in herbivores -

Answer 24

• grass is cut by teeth + mixed with saliva to form cud.
• Enters the rumen where cellulose digesting microbes produce glucose.
  -Glucose is fermented into organic acids and absorbed into the blood (produces methane + co2
  -fermented grass passes into the reticulum where it is re-formed into cud
• cud is regurgitated
  -the absomasum digests protoens
  -passes into small intestine

Question 25

What is a Parasite?

Answer 25

an organism that obtains nutrients from other living organisms - it causes harm

Question 26

What must the tapeworm survive?

Answer 26

-surrounded by digestive juice
-withstand peristalsis
-experience changes in Ph
-if the host dies, so does the parasite

Question 27

4 ways the parasite is adapted to survive

Answer 27

-cuticle protects from immune system
-produces enzyme inhibitors
-large SA to Vol ratio
-hermaphrodite- aesexual reproduction

Question 28

Name the 4 parts of the large intestine

Answer 28

-appendix
-caecum
-colon
-rectum

Question 29

Role of mutualistic organisms in the large intestine

Answer 29

• secrete folic acid and vitamin K in colon

Question 30

Where is water absorbed ?

Answer 30

colon - large intestine

Question 31

What extra tissue does the stomach wall have?

Answer 31

• oblique muscle