B3 Flashcards
What is an organelle?
A sub-cellular structure that carries out a specific function within the cell
Examples of organelles
Nucleus, Cytoplasm, Mitochondria, Cell membrane, Cell Wall, Ribosomes, Vacuole, Chloroplasts
What is a cell?
The basic unit of all living things
Example of cells
blood cells, nerve cells, sperm cells, root hair cells etc.
What is a tissue?
A group of cells that act together to perform a specific function.
example of tissues
Muscle tissue, Glandular tissue, Epithelial tissue
What is an organ?
A group of different tissues that work together to perform a certain function.
Example of organs
heart, lungs, brain, stomach etc.
What is an organ system?
A group of organs working together to perform a particular function
example of organ system
digestive system, nervous system, circulatory system, skeletal system, reproductive system etc.
What is an organism?
A living thing
What is a catalyst?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
What are enzymes?
Biological catalysts that speed up chemical reactions
What are enzymes made of?
Proteins which are synthesised in the ribosomes
4 types of enzymes?
Protease, Amylase, Lipase, Carbohydrase
Which part of the enzyme does the substrate bind to?
Active site; also where the reaction occurs
What are carbohydrates?
sugars and starches
What are carbohydrates used for?
Provide energy to the body, particularly through glucose, a simple sugar that is a component of starch and an ingredient in many basic foods.
What is starch broken down into?
glucose and maltose
What enzyme breaks down starch?
amylase
What are lipids?
fats and oils
What are lipids used for?
long term energy storage
What are lipids broken down into?
fatty acids and glycerol
What enzyme breaks down lipids?
lipase
What are proteins?
polymers of amino acids
What are proteins used for?
growth and repair
What are proteins broken down into?
long chains of amino acids
What enzyme breaks down proteins?
protease
Where is amylase produced?
Salivary glands, pancreas, small intestine
Where is protease produced?
Stomach, pancreas, small intestine
Where is lipase produced?
Pancreas and small intestine
Test for starch
Iodine solution
-Positive: Blue-black
-Negative: Orange-yellow
Test for sugars (glucose)
Benedict’s solution + heat
-Positive: Orange-red
-Negative: No change (blue)
Test for protein
Biuret solution
- Positive: Purple
- Negative: No change (blue)
Test for fats/oils (lipids)
Ethanol and Water (emulsion)
- Positive: Cloudy White layer
- Negative: No cloudy white layer
Factors affecting enzyme activity
Temperature, pH, enzyme concentration, substrate concentration
Name given to the shape of the active site when it has changed and the substrate can no longer bind
Denatured
Optimum temperature for enzymes
37˚C body temp
Where is hydrochloric acid produced?
Stomach
Where is bile produced and stored?
In the liver and stored in the gall bladder
function of hydrochloric acid
helps break down food
function of bile
emulsify (break down) fats
where is bile released?
small intestine
pH of stomach
Acidic
pH of small intestine
Alkaline
