Nutrition Flashcards
Define the term parasite and give an example (2)
- live in or one a host and obtain nutrient whilst harming the host
- tapeworm/ticks/leeches/headlice
Describe the terms autotroph and give an example (2)
- use simple inorganic molecules to synthesise organic compouns
- plant/algae
Describe the term saprophyte and give an example (2)
- secrete enzymes onto foood outside the body and absorb soluble products
- bacteria/fungi
Describe two features of an epithelium cell and explain why it is impotant for cell to function effieintly (4)
- microvilli
- increase surrface area for diffusion
- mitochondria
- synthesis of ATP for active transport
What is the function of goblet cells (1)
- secretes mucus
Where is the main regions in human gut where digestion and absorption occurs (2)
- digestion - mouth ,stomach,small intestine
- absorption - small intestine , large intestine
Explain why the human digestive system is divided into several regions (1)
- different parts carry out different functions
- provide differnt conditions for enzymes
- difference food groups digested in different areas
Suggest why it is a benefit for tapeworm to live in small intestine (1)
- region has hgih concentration of products of digestion
- tapeworm can absorb nutrients
- nourishment from digested food
How are tapeworms adapted overcome persitalsis and digestive enzymes (2)
- peristalsis - hooks and suckers attatch to gut wall
- digesive enzymes - thick cuticle/secretes muscus/secretes enzyme inhibitors
Suggest why tapeworms produce large number of eggs (1)
increases chance of surrvival / infeting a new host / many eggs will not survive
Which is the most acidic region of the alimetnary canal (1)
- stomach
In which two areas are proteins,carbohydrates and lipids digested together (1)
- duodenum
- ileum
Where does the process of protein digestion begin (1)
- stomach
Where is the main site of lipase production (1)
- pancreas
The setion of the alimentary canal where most absorption of digested products occur (1)
- ileum
The section of the alimentary canal whose main function is to absorb water (1)
- large intestine /colon
Explain how the jaw and teeth in herbivores are adapted for their nutrition (3)
- large molars for grinding
- diastma to manipular food
- well developed incisors for tearing vegetation
- very small / no canines
- loos articulation jaw moves in horizontal plame
- open roots to allow continous growth is molars
Explain how the gut of a herbivore is adapted for digestion (2)
- four chembered stomach
- contain cellulose digesting bacteria
- long gut allow extra time for digestion of cellulose
- cud is regurgitated for further chewing
Describe how the tapeworm is adapted to obtain its nutrients (3)
- attaches to gut wall by hooks and suckers
- large surface area to volume ration
- digested in host gut absorbed into tapeworm
- short diffusion pathway
Explain how hooks andd suckers help the adult tapeworm to survive (2)
- atttach to the gut wall
- worm does not get movedalong via persitalsis /prevent it being egested
State why the adult tape worm does not need a digestive system and explain how the worm body enables it to feed without moth of gut (3)
- lives surrounded by food that has been digested down by human digestvie system
- long large surface area to absorb digested food
- thin short sdiffusion distance
Describe how the tapeworm’s reproductive strategy helps to ensure its survival (2)
- large numbers of eggs
- eggs can resist adverse conditions
Give an account of sequence of events take place during digestion and absorption of meal containing carbohydrate and protein (10)
- in buccal cavity
- teeth mechanically break down food
- salive from salivary glands
- saliva containss mucus to lubricate
- amylar substrate is starch product is maltose
- stomach adapted for protein digestion
- produces hydrochloric acid
- peptidase is protein products are polypeptides
- small intestine adapted to complete protein digestion
- protease produced in small intestine
- pancreas produce lipase and amylase
- endo peptidase and exo peptidase
- absorption takes place in ileum
- villi increase surface area
- glucose are absorbed by diffusion and active transport
Explain two features are important in functioning of the villus (4)
- microvilli
- increase surface area for greater absorption of digested products
- large capillary network - transport glucose maintain diffusion gradient
- lacteal - absrob lipids
- thin epithelium - short diffusion parthway
Explain two functions of the secretion of mucus via goblet cells for process of digestion (2)
- reduced frictions for passae of food
- prevents effect of acid on gut wall
Layers of smooth muscle are found in wall of small intestine explain the role of these muscle layers in process of digestion (3)
- peristalsis
- circular and longitudinal muscles contract
- forces food along
Amino acids are absorbed and transported to live what are the fate of excess amino acids (2)
- deamination
- reamainder to carbohydrate
State three feature of gut parasites adaption to parisitic way of life (3)
- hooks and suckers for attathment to gut
- large surface area to volume ration
- thin
- covering resistant to digestive enzymes
- produce large number of eggs
Give reasons from dentition of a carnivorous diet (2)
- large carnines for tearing / killing prey
- molars for slicing meat
- small inciors for gripping flesh
- carnassials for crushing
- vertical movements of jaws
Describe similar mode of nutrition between carnivores and parasites (1)
obtains food from other organisms / heterotrophs
describe how parasitic nutrition is different to carnivores (2)
- parasites requires digested food by host whereas carnivores have digestive system
- parasites absorb food externally whereas carnivores is interal absorption
With reference to structure of starch and cellulose explain why alpha amylae is unable to digest cellulose even through starch and cellulose are polymers of glucose (3)
- reference active site of alpha amylase and ock and key theory
- complementary shape only to starch not cellulose
- starch contain alpha glucose but cellulose contain beta glucose
- regerence to coloiling in starch and straight chains in cellulose
Why do endopeptidase act before exopeptidase (2)
- endopeptidase hydrolyse peptide bonds in middle of polypeptide chain creating smaller polypeptides
- many peptides increase number of terminal peptide bonds for exopeptidases to hydrolyse
Use examples of sheep and tapeworm and describe and explain the structural adaptations they possess for particular mode of nutrition (10)
- sheep
