Adaptations for nutrition Flashcards
1
Q
What is autotrophic nutrition
A
make own food from simple inorganic raw materials
2
Q
What is photoautotrophic nutrition
A
use light energy to perform photosyntheis eg green plants , protoctista, some bacteria, autotrophic
3
Q
What does chemoautotrophic mean
A
use energy from chemical reactions prokaryotes autotrophic
4
Q
What does heterotrophic mean
A
consumes complex organic molecule produced from autotrophs
5
Q
What does saprotrophic mean
A
feed on dead or decaying matter by secreting enzymes extracellularly and absorb products eg bread mould heterotrophs
6
Q
What does parasitic nutrition mean
A
- obtain nutrition form another living organisms called host over long periods of time whilst causing it harm
- endoparasites live within hosts body eg tapeworm
- extoparasites live on surface eg human head lice
- heterotrophs
7
Q
What does holozoic nutrition mean
A
- form of nutrition used by most animals where ingest and digest food absorbing nutrients
- possesses a specialised digestive system
- herbivores (plant materials)
- carnivores (animal material)
- omnivores (plants and animal material)
- detrivores
- (dead or decaying matter)
8
Q
Descrbie nutrition in unicellular organisms
A
- protoctista such as amoaba are holozoic heterotrophs
- absorb nutrients directly throguh cell membrane via diffusion , ingesting larger molecules via endocytosis
- and fluids by pinocyotisis into food vacuoles
- lysosomes fuse with vacuoles release digestive enzymes
- nutrients are absorbed throguh membrane of food vacuole waste is ejected by exocytosis
9
Q
Describe nutritionin multicellular organisms (hydra)
A
- some larger organisms have a single body opening eg hydra
- live in fresh water
- tentacles paralyse prey and move into a hollow body cavity through mouth
- protease and lipase enzymes digest food extracellularly products are absorbed before indigestivle remains egested back out through mouth
- more developed organisms possess a tube gut ingest one end egesting the other most advances posess a specialised region
10
Q
Describe the human digetive system
A
- gut consists of a long hollow muscular tube through which food eases along by peristalsis
- ingestion - taking in food via mouth brining it into contact with digestive surface
- digestion - larger biological molecules hydrolysed to smaller molecules absorbed across cell membrane it starts wtih mechanical digestion in mouth involveing teeth breaks large food pieces into smaller pieces completed by enzymes
- absorption - passage of nutrient molecules through wall of gut into blood
- egestion - elimination of undigested material eg cellulose fibre
11
Q
What is the structure of the gut wall
A
- consiste of four layers
- serosa
- muscle
- submucose
- mucosa
12
Q
describe what the serosa does in the gut wall
A
- outermost layer consisting of tough connective tissue which protects the gut reducing friction from other abdominal organs
13
Q
Describe what does the muscle does in the gut wall
A
- two layer circular and longitudinal smooth muscle contract in coordinated fashion pushing food along by peristalsis
14
Q
Describe what does the submucosa does in the gut wall
A
- connective tissue containing blood and lymph vessels to take away absorbed products of digestion
- nerves are present co ordinate muscular contractions
15
Q
Describe what does the mucosa does in the gut wall
A
- inermost layer lining gut secrete mucus lubrication and protection from enzymes
- depend upon region secretes enzymes absorbs digested food and nutrients
16
Q
What is digestion
A
- different food groups subsequent absorption takes place in different parts of the gut
- different enzymes digest different food groups
17
Q
How are carbohydrates digested
A
- amylase hydrolyses starch to maltose then maltase hydrolyses maltose to glucose
- sucrase hydroluses sucrose into glucose and fructose
- lactase hydrolyses lactose to glucose and galactose
18
Q
How are proteins digested
A
- digested into polypeptides, dipeptides eventually amino acids
- enzyjmes are peptidases according to where vrean peptide bonds
- from the end are exopeptidase
- from the middle are endopeptidase
- and dipeptide seperating a dipeptide
19
Q
How are fats broken down
A
- emulsified by bile hydrolysed into fatty acids and glycerol
20
Q
How is the mouth involved in digestion
A
- buccal cavity
- where digestion begins
- teetch mechanically digest food tongue mixes with saliva rolls into a bolus for swallowing
- saliva contains enzyme amylase , mucus lubricates food
- amylase initiates starch digestion
21
Q
How is the oesophagus involved in digestion
A
- mucles contract moving food down towards the stomach via peristalsis
22
Q
How is the stomach involved in digestion
A
- food is digested by muscular action from stomach walls and gastric juices whcih contains hydrochloric acid and pepsin
- pepsin is an endopeptidase secreted in an inactive form of pepsinogen activated by H+ ions prevent pre digestion
- acidic Ph 2 also kills bacteria
- mucus is produced by goblet cells in gastric pits and lubricates foods and protects the lining
23
Q
Describe how the duodenum is involved in digestion
A
- first part of small intestine recieveing secretions from liver and pancreas
- bile contains bile salts neutralising acidic food from stomach and emulsifies fats
- pancreatic juice alkaline due to sodium hydrogen carbonate
- pacreatic juice is secreted by islet cells in pancreas entering duodenum via pancreatic duct
- contains endopeptidases and trypsiongen which is inactive converted into active trypin by engerokinase
- amylase and lipase
- brunner’s glands at base of crypts produce alkaline secretions also neutralise acidic food from stomach
- mucosa of small intestine is heavily folded froming villi
- in duodenu, endopeptidases and exopeptidases are secreted by cells at tip of villi and peptidases that bond to epithelial cell complete digestion to amino acids
- matlase , lactase , sucrase are bound to epithelial cells complete digestion of carbohydrates
24
Q
Describe the role of the ileum in digestion
A
- second part of small intestine is responsible for the absorbtion of digested food
- villi and microvilli greatly increase surface aerea for flew absorbtion by diffusion, facilitated diffusion , co transport and active transport and for action of membrane bound enzymes
- glucose enters epithelial cells by co transport and active transport by facilitated diffusion into capillary of villus
- amino acids enther by active traansport into epithelial cells and then by facilitated diffusion into capillary of villus
- fatty acids and glycerol enter by epithelial cells via diffusion where recombine into triglycerides and enter lacteal of villus
- in epithelial cells smooth endoplasmic reticulum highly developed to addidt this process
- water absorbed by osmosis into epithelial cells into capillary of villus
- water soluble bitamins absorbed directly into blood while fat soluble vitamin absorbed into lacteal by diffusion
25
What is the role of the large intestines in digestion
* small villi present and responsible dor absorbtion of water formation of faeces stored in the rectum until egested
* mutualistic bacteria in colon responsible for production of vitamin K and folic acid
* glucoe and amino acids and transported by hepatic portal vein to liver where they are processed
* lactaksdrain into lymohatic systam drainns blood via thoraic duct right before subclavian vein
26
What are the adaptations for carnivores
* evolved sharp inciors to tear flesh pointed canines pierce flash kill prey specialised molars called carnisials shear flesh and bone
* powerful jaw muscles move lower jaw vertically up and down and able to open jaws wide accomodate large prey
* intestines relativley short main constituent in diet iss protein relativley easily digested
27
What are ruminanats and their adaptations
* include cows and sheppes highly modified oesophagus
* grasss is chewed form a bolus known as cud swallowed enters rumen mixes with mutualitic cellulose digesting bacteria produce glucose from cellulose
* glucose is anaerobically respired by bacteria producing organic acids carbon dioxide and methane as waster products
* remaining grass passes to the reticulum where reforemd into cud which is regurgitated rechewed to increase surface area for action of bacterial cellulase before being swallowed again
* cud passes to omasum where organic acids are absorbed into blood
* finally material passe to abomaum (true stomach) where acid kills baceria and pepsin begins digestion of bacteria
* water is absorbed in the large intersitines in a similar way as in humans
28
How are herbivores adapted
* interlocking molar teeth rough prescence sharp enaels ridges teetch worn down by abrasive plant material grow continuoulsy
* jaw moves sidewaus aid grinding food
* vegetative diet made of cell walls in plant tisues call cellulose
* made og beta glucose into microfibrils make cellulose difficult to digest
* incisors and cnine slice vegetation cropping it
* lack incisors porsess a horny pad lower teetch cut against it
* gap called diastema allow food to me mixed during chewing processes
29
What are parasites and briefly explain tape worms
* parasits live in (endoparasites) or on (ectoparasites) a host organisms causing harm
* pork tapework has two hosts (host in which sexual reprpduction tales place in human) and pig is secondary host
* btoh needed to fully complete parasites life cycle if eggs directly eaten by human than infected meat cysts that can form in the brain
30
What are adpatations of the tape worm
* suckers and hooks - attatchment to gut wall
* thin and large surface area to volume ratio - maximise absorption of digested food
* produce enzyme inhibitors - prevent digestion by host's enzyme
* thick cuticle - protect from host's immune reposnses
* male and female reproductive systems - allow reproduction without second tapeworm
* produce vast number of eggs - incrases chance of finding another host
* eggs have resistant shells - survive until eaten by secondary host
31
How does the tape worm get it's nutrients
* not have a digestive system absorbs products of host's digestion directly through cuticle
32
What are head louse and how are they adapted to be parasites
* ectoparasite
* feed sucking blood from scalp of host
* wingless insects only pass to new host via direct contact
* they lay eggs attatch to hair
* legs are adapted to be claw like to grip onto hair
* lay eggs glued to base of hairs
33
Parasitic nutrition
involves obtaining nutrients from a host organism over a long period of time casuing it harm in the process
34
Peristalsis
the wave of coordinated contracttion and relaxation of smooth muscles in the gut
35
Hydrolysis
reaction involving chemical addition of water to break bond formed during condensation
36
Emulsification
large fat droplets broken into smaller droplets which increases the surface area for lipase action
37
Carnassials
modified upper premolar and lower molar teeth found in carnivores that have a scissor like action for slicing bone and flesh
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