B3 - Organisation and the Digestive System

tissues

group of cells that act together to perform a similar function

epidermal tissue

Human skin and the waxy covering of some plants

mesophyll

spongy tissue for photosynthesis

muscular tissue

contracts and moves the various parts of the body

epithelial tissue

lining of organs and blood vessels

glandular tissue

Produces digestive juices that break down food

large intestine

Absorbs water and forms feces

small intestine

digests food and absorbs soluble food molecules

stomach

digests food

liver

produces bile

glands

produce digestive enzyme

levels of organism

cell, tissue, organ, organ system, organism

organism

highest level of organisation consisting of several organ systems

organ

Groups of tissues that work together to perform a specific function

cell

fundamental unit of life

organ system

groups of organs that work together to perform a specific function

examples of glands

pancreas and salivary glands

enzyme

biological catalyst that is a protein

active site

a region on an enzyme that binds to a specific substrate

denatured

altered structure of an enzyme that can no longer catalyse

rate of reaction

gradient of graph

Factors that affect enzyme activity

temperature and pH

rate of reaction

change in mass / change in time

how are digestive enzymes made

specialised cells in glands and gut lining

breakdown of large food molecules

catalyses of digestive enzymes, soluble molecules are absorbed into bloodstream, glucose produced used for respiration

3 main digestive enzymes

amylase, protease, lipase

amylase

breaks down starch into smaller molecules

protease

breaks down proteins into amino acids

lipase

breaks down lipids into fatty acids

bile

alkaline substance produced in liver and stored in gallbladder

emulsification

bile breaking fats into tiny droplets

benefit of emulsification

bile creates larger surface area which makes rate of reaction faster

ph of small intestine enzymes

alkaline

why does bile neutralise stomach acid

to stop enzymes becoming denatured

sites of action of amylase

small intestine and mouth

production of amylase

pancreas, salivary glands, small intestine

sites of action of protease

small intestine and stomach

production of protease

Stomach, pancreas, small intestine

sites of action of lipase

small intestine

production of lipase

pancreas, small intestine, stomach

how to test for sugar

benedicts solution and will turn green yellow or red

how to test for lipids

ethanol and will turn cloudy

how to test for starch

iodine solution and will turn blue black

how to test for proteins

biuret solution and will turn purple

purpose of hydrochloric acid

kills bacteria

pancreatic enzymes

work best in alkaline solutions

increasing concentration of enzyme and substrate

increases number of active sites/substrate molecules and rate of reaction increases

function of pancreas

makes digestive enzymes