organisation and digestive system

what happens as the multicellular organism develop

they differentiate and perform different jobs

tissue

A group of similar cells that perform the same function.

muscular tissue

Contracts and moves the various parts of the body.

glandular tissue

produces enzymes and hormones

epithetical tissue

A body tissue that covers the surfaces of the body, inside and out

organs

Groups of tissues that work together to perform a specific function or related functions

what tissues are in the stomach

muscular, glandular, epithelial

muscular tissue in the stomach

churn the stomach content

glandular tissue in the stomach

Makes digestive juices to digest food

epithelial tissue in the stomach

covers the outside and inside of the stomach

Pancreas

Regulates the level of sugar in the blood

what are the two types of glandular tissue in the pancreas

• hormones to control the blood sugar

• digestive enzymes

What are multicellular organisms made up of?

organ systems

what do organ system include?

digestive system, circulatory system and gas exchange system

digestive system

body system the breaks down food and absorbs nutrients

name two glands in the digestive system

pancreas and salivary glands

stomach

large muscular sac that continues the mechanical and chemical digestion of food

liver

produces bile

small intestine

The part of the digestive system in which most chemical digestion takes place.

large intestine

Absorbs water and forms faeces

Oesophagus

Tube connecting the mouth to the stomach

gall bladder

organ that stores bile

rectum

the final section of the large intestine, terminating at the anus.

carbohydrates

the starches and sugars present in foods

glucose

A simple sugar that is an important source of energy.

complex carbohydrates

starch and cellulose is made of long chain of simple sugar units that are bonded

lipids

fats and oils

glycerol

Combines with fatty acids to make lipids.

proteins

Chains of amino acids

denatured

when protein is heated and the shape changes and the protein denatures

iodine test for starch colour

yellow-red iodine solution turns blue-black if starch is present

benedict's test for sugars colour

blue benedict solution turns brick red if glucose is present

biuret test colour

blue biuret reagent turns purple/blue if protein is present

ethanol test colour

ethanol is added to a solution and gives a cloudy white layer if lipids are present

what are chemical reactions in a cell controlled by?

proteins called enzymes

what is an enzyme

biological catalyst

active site

a region on an enzyme that binds to a protein or other substance during a reaction.

features of enzymes

• build larger molecules from many smaller ones

• converts molecules

• breaks down molecules into smaller ones

metabolism

sum of all reactions that take place in a cell or the body

how is enzyme- catalysed reaction similar to other chemical reactions

when the temperature increases the enzyme-catalysed reaction increases

what happens when the temperature is to high for the enzyme?

it stops working and the shape denatures

does stomach work best in acid or alkali

acid

how is an enzyme held together

The shape of an active site of an enzyme comes from forces between the different parts of the protein molecules. .

how can pH effect the enzyme activity

• optimum pH for an enzyme has the highest enzyme activity

• if ph is too acidic or alkaline the enzyme denatures

what does digestion involve

The breakdown of large insoluble molecules into soluble substances that can be absorbed into the blood across the wall of the small intestine.

digestive enzymes features:

• produced in glands by specialised cells

• pass out glands into the lining of the digestive system

• come in contact with food so it can digest

the digestive system features:

• breaks down to increase the surface area for the enzyme

• mix food with digestive juice that contains enzyme

• muscles move food

• different pH levels

amylase

Enzyme in saliva that breaks the chemical bonds in starches

proteases

Enzymes that break down proteins into amino acids

lipase

enzyme that breaks down fat to fatty acid and glycerol

where does digestive work best

body temperature ( 37 degrees Celsius)

what do glands in the stomach wall produce?

hydrochloric acid

bile

• neutralises the stomach acid

• emulsifies fat to increase surface area of fat for lipases enzyme

• makes small intestine slightly alkaline