Adaptations for nutrition Flashcards
What is autotrophic nutrition
make own food from simple inorganic raw materials
What is photoautotrophic nutrition
use light energy to perform photosyntheis eg green plants , protoctista, some bacteria, autotrophic
What does chemoautotrophic mean
use energy from chemical reactions prokaryotes autotrophic
What does heterotrophic mean
consumes complex organic molecule produced from autotrophs
What does saprotrophic mean
feed on dead or decaying matter by secreting enzymes extracellularly and absorb products eg bread mould heterotrophs
What does parasitic nutrition mean
- 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
What does holozoic nutrition mean
- 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)
Descrbie nutrition in unicellular organisms
- 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
Describe nutritionin multicellular organisms (hydra)
- 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
Describe the human digetive system
- 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
What is the structure of the gut wall
- consiste of four layers
- serosa
- muscle
- submucose
- mucosa
describe what the serosa does in the gut wall
- outermost layer consisting of tough connective tissue which protects the gut reducing friction from other abdominal organs
Describe what does the muscle does in the gut wall
- two layer circular and longitudinal smooth muscle contract in coordinated fashion pushing food along by peristalsis
Describe what does the submucosa does in the gut wall
- connective tissue containing blood and lymph vessels to take away absorbed products of digestion
- nerves are present co ordinate muscular contractions
Describe what does the mucosa does in the gut wall
- inermost layer lining gut secrete mucus lubrication and protection from enzymes
- depend upon region secretes enzymes absorbs digested food and nutrients