B3-Organisation and the digestive system Flashcards
Cell definition
The basic building block of all living organisms
Organelle definition
A specialised unit within a cell that performs a function
Tissue definition
A group of cells with similar structure working together
Organ definition
Different tissues working together to perform a specific function
Organ system
A group of organs with related functions working together
Levels of organisation
Organ, cell etc
Organelle-cell-tissue-organ-organ system-organism
Epithelial tissue
Covers the inside and outside of the stomach to protect from acidity
Glandular tissue
Secretes digestive enzymes to break down the food
Muscular tissue in stomach
Churn food and digestive juices together by contracting
Digestion definition
Breakdown of large insoluble food molecules into small, soluble to be absorbed into the bloodstream
Proteins
Made up of?
Needed for?
Found in?
Amino acids
Growth and repair
Meat, eggs, nuts
Lipids
Made up of?
Needed for?
Found in?
Glycerol and fatty acids
Long term energy, growth
Butter, oily fish, nuts
Carbohydrates
Made up of?
Needed for?
Found in, starch, sugar?
Sugars like glucose
Quick or slow release energy
Starch- rice, bread, pasta
Sugar-fruit, chocolate
Food test for protein?
Negative result?
Positive result?
Biuret solution
Blue
Purple
Food test for lipids?
Negative result?
Positive result?
Ethanol
Clear liquid
Cloudy white layer on top
Food test for carbohydrate, starch?
Negative result?
Positive result?
Iodine solution
Yellow/orange
Dark blue/black
Food test for carbohydrate, sugar?
Negative result?
Positive result?
Benedicts solution and heat
Blue
Green or brick red
Catalyst
Speeds up chemical reactions without being used up itself
Metabolism
Sum of all reactions in a cell or the body
Enzyme definition
A biological protein catalyst that speeds up chemical reactions without being used up
Describe the lock and key model
Substrate binds to enzyme as substrate is complementary to active site of enzyme, forms enzyme-substrate complex. Reaction, products released
Denatured meaning
When the active site of the enzyme is no longer complementary to the substrate
Factors that affect enzymes
pH, temperature, substrate concentration
Calculating rate of reaction equation
Rate of reaction= quantity of product (g)
/ time taken (s)
Temperature rate of reaction graph
Increases at first, ↑temp ↑KE ↑successful collisions, reaches optimum, then 40 degrees roughly enzymes become denatured. Then decreases as enzymes stop working
pH rate of reaction graph
Low rate of reaction, denatured enzymes
Fastest rate, optimum
Low rate of reaction, denatured enzymes
Substrate conc rate of reaction graph
More substrate than active sites filled
Once all sites taken, no more binding, point of saturation, same rate
Amylase
Breaks down?
Found in?
Starch to simple sugars
Saliva, small intestine, pancreas
Protease
Breaks down?
Found in?
Protein to amino acids
Stomach, small intestine, pancreas
Lipase
Breaks down?
Found in?
Fats to glycerol and fatty acids
Small intestine, pancreas
Method for the effect of temp on the rate of reaction of amylase?
Add 2cm3 of starch to a test tube, label S. Add 2cm3 of amylase to a test tube, label A.
Repeat, so you have 4 test tubes.
Place one of S and A in a water bath at 37° for 10 mins
Use spotting tile, place drop of iodine in each space
Meanwhile, put room temp tube A into tube B. Start stop clock while adding one drop to first space on spotting tile. It will turn black.
Every 30s add another drop to next space until it remains orange.
Repeat with test tubes from water bath.
What enzyme is in the stomach and how is the stomach suited for it?
Protease best in acidic conditions, stomach produces hydrochloric acid, low pH
What enzymes are found in the pancreas and taken to small intestine?How suited?
Amylase, lipase work best in alkaline conditions
Bile neutralises stomach acid
Bile
Produced, stored?
2 jobs?
Produced by liver, stored in gallbladder
Neutralises stomach acid in small intestine
Emulsifies fats to improve sa for lipase
