B2 Flashcards
What are the smallest level of the organisation ?
cell , tissue , organ , organ system , organism
What is the definition of a cell?
- basic building block of all organisms
What is the definition of a tissue?
- a group of cells with a similar structure and function
What is the definition of an organ?
- a group of tissues working to complete a particular function
What is the definition of an organ system?
- a group of organs which work together to form an organism
What happens in the digestive system?
- in the digestive system enzymes break down large, insoluble, molecules into smaller soluble ones
- which can be absorbed into the bloodstream
What are the parts of the digestive system?
- mouth
- salivary gland
- oesophagus
- liver
- stomach
- pancreas
- large intestine
- small intestine
- rectum
- anus
What is the function of the salivary glands?
- produce the amylase enzyme to start digestion
What is the function of the stomach?
- produce the protease enzyme to digest food
What is the function of the liver?
- produces bile to neutralise stomach acid and emulsify fats
What is the function of the pancreas?
- produces digestive enzymes
What is the function of the small intestine?
- where digested, small soluble molecules are absorbed into bloodstream
What is the function of the large intestine?
- water from undigested food is absorbed
What is an enzyme?
- it is a protein molecule which can speed up reactions
What is a catalyst?
- is a substance which increases the speed of a reaction without being changed or used up in the reaction
Describe what is meant by lock and key theory
- the substrate fits into the active site of the enzyme
- the enzyme then breaks the substrate into the products which are released from the active site
- the enzyme is not used up in the reaction and will be able to break down another substrate molecule
Why do we say that enzymes are specific?
- enzymes are specific because the active site is a particular shape and only one type of substrate can fit
What do we mean when we say an enzyme has denatured?
- if an enzyme is in the wrong conditions it can denature
- this is where the active site changes shape so the substrate won’t fit anymore
What will happen to the rate of reaction when the temperature increases?
- if the increase in temperature makes the rate of reaction increases up to the optimum temperature
- after this, the active site of the enzyme starts to change shape , the substrate won’t fit and the enzyme is denatured
What will happen to the rate of reaction when the pH is too low or too high?
- if the pH is too low or too high the active site of the enzyme starts to change shape, the substrate won’t fit and the enzyme is denatured
- the pH the enzyme works best at is called the optimum pH
What does carbohydrase (an example) break down and where its made in?
- example would be amylase
- it breaks into starch
- into sugar (glucose)
- its made in the : salivary glands , pancreas & small intestine (SI)