P1 - Organisation Flashcards
Why are muscle cells packed full of mitochondria?
To provide the energy needed for contraction
What’s a tissue?
A tissue is a group of cells with a similar structure and function
What’s an organ?
An organ is a group of tissues working together for a specific function
What 2 tissues does the stomach contain which release enzymes?
- Muscle tissue
- Glandular tissue
What’s an organ system?
A group of organs
What’s an organism?
A group of organ systems
What are the 3 main nutrients that food contains?
- Carbohydrates
- Protein
- Lipids
TRUE OR FALSE: Carbohydrates, protein and lipids are small enough to be absorbed into the bloodstream
FALSE: Carbohydrates, protein and lipids are large molecules that have to be digested
Once large food molecules are broken down, what happens?
They’re broken down into small molecules by enzymes and are absorbed into the bloodstream
What’s the function of the mouth in the digestive system?
To chew food and the enzymes in the saliva begin to digest the starch into smaller sugar molecules
What’s the function of the oesophagus?
To pass food from the mouth to the stomach
What’s the function of the stomach?
- To digest proteins with enzymes
What does the hydrochloric acid in the stomach do?
Helps the enzymes to digest proteins
How long does food spend in the stomach?
Several hours
What does the churning action of the stomach muscles do?
Turns the food into a fluid which increases the surface area for enzymes to digest
What’s the function of the small intestine?
To absorb small food molecules into the bloodstream by diffusion or active transport
Chemicals are released into the small intestine, where do they come from?
The liver and the pancreas
What’s the function of the pancreas in the digestive system?
The pancreas releases enzymes which continue the digestion of starch and protein and start the digestion of lipids
What’s the function of the liver in the digestive system?
The liver releases bile
What are 2 functions of bile?
- Speeds up the digestion of lipids
- Neutralises the acid released from the stomach
What does the walls of the small intestine release during the digestive system?
Enzymes to continue the digestion of protein and lipids
What’s the function of the large intestine?
To absorb water into the bloodstream
What happens at the end of the digestive system?
Faeces are released from the body
What are the products of digestion used for?
To build new carbohydrates, lipids and proteins
Large food molecules are digested by enzymes into what?
Smaller molecules
Do enzymes speed up or slow down chemical reactions?
Speed up
What’s the active site of an enzyme?
It’s where the substrate attaches to
What’s the substrate?
The molecule the enzymes breaks down
What’s the theory that suggests the substrate must fit perfectly into the active site in enzymes?
The lock and key theory
What breaks proteins down?
Protease
Where is protease found?
- Stomach
- Pancreatic fluid
- Small intestine
Proteins are long chains of chemicals called what?
Amino acids
When we digest proteins, protease converts the protein back to what?
Invdividual amino acids
Extra: They’re then absorbed into the bloodstream
When amino acids are absorbed by the body cells, they are joined together in a different order to make what?
Human proteins
What does starch consist of ?
A chain of glucose molecules
What breaks carbohydrates down?
Carbohydrase
In the case of starch, what enzyme breaks it down?
Amylase
When carbohydrates are digested, what do we produce?
Simple sugars
Where is amylase found?
- Saliva
- Pancreatic fluid
What does a lipid molecule consist of?
Glycerol attached to three molecules of fatty acids
What breaks lipids down? Then what does it produce?
Lipase, it produces glycerol and fatty acids
Where do we find lipase?
- Pancreatic fluid
- Small intestine
Where is bile made and stored?
Made in the liver
Stored in the gall bladder
TRUE OR FALSE: Bile is an enzyme
FALSE: Bile is not an enzyme
When bile emulsifies the lipid, how does it affect the surface area of the lipid droplets? How does this affect the rate of lipid breakdown by lipase?
It increases the surface area
It increases the rate of lipid breakdown by lipase
