Cell Organisation, Enzymes And Digestion Flashcards
1
Q
What are cells
A
The basic building blocks that make up all living organisms
2
Q
What is a tissue, give examples
A
- A group of similar cells that work together to carry out a particular function
E.g. - Muscular tissue, which contracts to move whatever it’s attached to
- Glandular tissue, which makes and secretes chemicals like enzymes and hormones
- Epithelial tissue, which covers some parts of the body e.g. the inside of the gut
3
Q
What is an organ, give examples
A
- a group of tissues that work together to perform a certain function
E.g. in the stomach you have these tissues: - Muscular tissue, which moves the stomach wall to churn up the food
- glandular tissue, which makes digestive juices to digest food
- Epithelial tissue, which covers the outside and inside of the stomach
4
Q
What is an organ system, give an example
A
- A group of organs working together to perform a particular function
E.g. The digestive system which is made up of these organs - Glands (e.g. pancreas and salivary glands) which produce digestive juices
- The stomach and small intestine which digest food
- the liver, which produces bile
- The small intestine, which absorbs soluble food molecules
- The large intestine, which absorbs water from undigested food, leaving faeces
5
Q
What do organ systems work together to make
A
Organisms
6
Q
What is an enzyme
A
- Enzymes are biological catalysts produced by living things
- They are all large proteins and all proteins are made up of chains of amino acids
- These chains are folded into unique shapes, which enzymes need to do their jobs
7
Q
What is a catalyst
A
A catalyst is a substance which increases the speed of a reaction, without being changes or used up in the reaction
8
Q
Explain the ‘lock and key’ model
A
- Every enzyme has an active site with a unique shape that fits onto the substrate involved in the reaction
- Enzymes are specific.
- They only wok on the substrate that they “fit.”
- Just like a lock has a specific key to open it.
9
Q
Why do enzymes need the right temps
A
- the higher the temp the faster the rate of reaction
- however it can get too hot for the enzyme and at a certain point, the enzyme will become denatured
- This means that some of the bonds holding the enzyme together break, changing the shape of the enzyme’s active site, and so the substrate won’t fit anymore
10
Q
Why do enzymes need the right pH
A
- too high or too low can interfere with the bonds holding the enzyme together and denature it
- Often pH 7 is the optimum
With a few exceptions e.g. - pepsin = pH2 = because it is found in the stomach where it breaks down proteins
11
Q
What do digestive enzymes break down
A
BIG MOLECULES such as:
- Starch
- proteins
- Fats
12
Q
Why do the big molecules need to be broken down
A
- They are too big to pass through the walls of the digestive system, so digestive enzymes break them down into smaller ones
- These smaller, soluble molecules can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream
13
Q
What breaks down starch
A
- Carbohydrases convert carbohydrates into simple sugars
- Amylase is an example of a carbohydrase. It breaks down starch
- Amylase is made in the Salivary glands, pancreas, small intestine
14
Q
What breaks down proteins
A
- proteases convert proteins into Amino Acids
- made in: the stomach (pepsin), the pancreas, the small intestine
15
Q
What breaks down lipids
A
- Lipases converts lipids into glycerol and fatty acids
- Lipase is made: in the pancreas, the small intestine
