nutrition

Question 1

what is heterotrophic nutrition

Answer 1

organism that obtains complex organic molecules by consuming other organisms

Question 2

what is saprotrophic nutrition

Answer 2

derive energy and raw materials for growth from extracellular digestion of dead or decaying matter

Question 3

what is an autotroph

Answer 3

organism that makes its own complex organic molecules from simpler molecules using chemical or light energy

Question 4

how do saphrotrophs absorb nutrients

Answer 4

secrete enzymes onto food and absorb across cell membrane through
diffusion and active transport

Question 5

what is a chemoautotroph

Answer 5

use energy from chemical reactions
all prokaryotes and perform chemosynthesis

Question 7

what is an example of a saphrotroph

Answer 7

Rhizopus

Question 8

what is parasitic nutrition

Answer 8

obtaining nutrition from another living organism which suffers harm

Question 9

how do amoeba obtain nutrition

Answer 9

holizoic
large SA :V
absorb across membrane through diffusion facilitated diffusion and active transport

Question 10

how do hydra obtain nutrients

Answer 10

sting with tentacles to paralyse prey
move prey to mouth
endodermal cells secrete protease and lipase
prey digests extracellularly

Question 11

why does food have to be digested

Answer 11

molecules insoluble and to big to cross membranes and be absorbed

Question 12

what are the 4 functions of human gut

Answer 12

ingestion - taking food into buccal cavity
digestion - breakdown of large insoluble molecules into soluble molecules small enough to be absorbed into blood , either mechanical or chemical
absorption - passage of molecules and ions through gut wall into blood
egestion -elimination of waste not made by body

Question 13

what is serosa

Answer 13

outermost layer- tough connective tissue protects gut wall and reduces friction with other abdominal organs

Question 14

what do longitudinal and circular muscle do

Answer 14

make coordinated waves of contraction - peristalsis

Question 15

what is submucosa

Answer 15

connective tissue with blood and lymph vessels+ nerves to coordinate peristalsis
Removes absorbed products of digestion

Question 16

what is mucosa

Answer 16

innermost layer of gut wall
epithelium secretes mucus

Question 17

how are carbohydrates digested

Answer 17

carbohydrase
amylase digests starch to maltose
maltose digested by maltase to glucose

Question 18

how are proteins digested

Answer 18

proteases and peptidase

Question 19

what does gastric juice contain

Answer 19

peptidases - secreted by zymogen
pepsinogen activated by H+ ions to pepsin which breaks down proteins
hcl - Secreted by oxynitic cells lowers pH so it is optimum for enzymes
mucus to protect stomach wall

Question 20

what is bile made up of

Answer 20

amphipathic bile salts - emulsify lipids In food breaking it into smaller glubules so have a larger SA
alkaline and neutralises pH of food coming from the stomach so its a suitable pH for enzymes In Small intestine

Question 21

where does bile come from

Answer 21

made in liver
stored in gall bladder
passes through bile duct Into duodenum

Question 22

what in pancreatic juice made from

Answer 22

trypsinogen - converted into trypsin by enterokinase
endidopeptidases
amylase
lipase
sodium hydrogen Carbonate - raises pH to make it slightly alkaline

Question 23

where does pancreatic juice come from

Answer 23

secreted by islet cells in pancreas
enters duodenum through pancreatic duct

Question 24

how and where does absorbtion occur

Answer 24

mainly in the small intestine through diffusion , facilitated diffusion and active transport

Question 25

how do villi help absorption

Answer 25

create a large SA:V

Question 26

How are amino acids absorbed

Answer 26

move into epithelial cells through active transport then pass into capillaries through facilated diffusion as single amino acids and are water soluble so dissolve into plasma

Question 27

how is glucose absorbed

Answer 27

Co transported into epithelial cells with sodium ions into capillaries and dissolves in plasma

Question 28

how are fatty acids absorbed

Answer 28

diffusion

Question 29

how do minerals absorb

Answer 29

taken into blood by FD , D and AT

Question 30

What is the dentition of A HERBIVORE

Answer 30

inscisors on lower jaw only
diastema to allow tongue and cheeks room
molars interlock lower jaw moves side to side
open unrestricted roots to allow teeth to continually grow

Question 31

what is the dentition of a carnivore

Answer 31

sharp incisors to tear meat from bones
large canines
cusps on molars and premolars which are sharp
carnissials which slide past each other
vertical lower jaw movement to avoid jaw dislocation
strong jaw muscles

Question 32

what is the process of cellulose digestion

Answer 32

cud is formed and passes to rumen
cud mixed with microbes that digest cellulose to glucose which is fermented to organic acids and absorbed to blood
fermented grass passes into reticulum and reformed into cud
cud passes to omasum where organic acids absorb into blood
moves to abomasum and proteins digested by pepsin

Question 33

how are tapeworms resistant to the human stomach

Answer 33

scolex with suckers to grip to walls in the duodenum
thick cuticle to resist hosts enzymes and immune system
produce enzyme inhibitors
large surface area to absorb pre digested food over its whole surface