nutrition Flashcards
what is heterotrophic nutrition
organism that obtains complex organic molecules by consuming other organisms
what is saprotrophic nutrition
derive energy and raw materials for growth from extracellular digestion of dead or decaying matter
what is an autotroph
organism that makes its own complex organic molecules from simpler molecules using chemical or light energy
how do saphrotrophs absorb nutrients
secrete enzymes onto food and absorb across cell membrane through
diffusion and active transport
what is a chemoautotroph
use energy from chemical reactions
all prokaryotes and perform chemosynthesis
what is an example of a saphrotroph
Rhizopus
what is parasitic nutrition
obtaining nutrition from another living organism which suffers harm
how do amoeba obtain nutrition
holizoic
large SA :V
absorb across membrane through diffusion facilitated diffusion and active transport
how do hydra obtain nutrients
sting with tentacles to paralyse prey
move prey to mouth
endodermal cells secrete protease and lipase
prey digests extracellularly
why does food have to be digested
molecules insoluble and to big to cross membranes and be absorbed
what are the 4 functions of human gut
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
what is serosa
outermost layer- tough connective tissue protects gut wall and reduces friction with other abdominal organs
what do longitudinal and circular muscle do
make coordinated waves of contraction - peristalsis
what is submucosa
connective tissue with blood and lymph vessels+ nerves to coordinate peristalsis
Removes absorbed products of digestion
what is mucosa
innermost layer of gut wall
epithelium secretes mucus
how are carbohydrates digested
carbohydrase
amylase digests starch to maltose
maltose digested by maltase to glucose
how are proteins digested
proteases and peptidase
what does gastric juice contain
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
what is bile made up of
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
where does bile come from
made in liver
stored in gall bladder
passes through bile duct Into duodenum
what in pancreatic juice made from
trypsinogen - converted into trypsin by enterokinase
endidopeptidases
amylase
lipase
sodium hydrogen Carbonate - raises pH to make it slightly alkaline
where does pancreatic juice come from
secreted by islet cells in pancreas
enters duodenum through pancreatic duct
how and where does absorbtion occur
mainly in the small intestine through diffusion , facilitated diffusion and active transport
how do villi help absorption
create a large SA:V
How are amino acids absorbed
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
how is glucose absorbed
Co transported into epithelial cells with sodium ions into capillaries and dissolves in plasma
how are fatty acids absorbed
diffusion
how do minerals absorb
taken into blood by FD , D and AT
What is the dentition of A HERBIVORE
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
what is the dentition of a carnivore
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
what is the process of cellulose digestion
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
how are tapeworms resistant to the human stomach
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
