Organisation Flashcards
What is a tissue
a group of cells working together to complete a specific function
What is an organ
a group of tissues working together to complete a specific function
What is an organ system?
a group of organs working together to complete a specific function
What are the three main nutrients gained from foods?
- Carbohydrates
- proteins
- lipids (fats)
- all these are large molecules. They have to be digested as they can’t be absorbed into the blood stream
What is digestion?
The break down of large food molecules into smaller ones via digestion so it can be absorbed into the blood stream
What is the first stage of the digetive system?
- first food is chewed in the mouth
- amylase in the saliva begin to digest starch into smaller sugar molecules
- the saliva helps make the food into a bulas, so the food can pass down into the oesphagus
What is the second stage of the digestive system
- the oesphagus squeezes the food down the oesphagues into the stomach
- the food passes into the stomach. This is where the digestion of proteins begins. There is also HydroCloric acid in the stomach. This helps to break down the proteins.
- There is a churning action in the stomach that turns the food into a fluid, increasing surface area for enzymes to digest
What is the third stage of the digestive system
- the fluid passes into the digestive system.
- the pancreaus and liver release chemcials into the small intestine.
- the pancreus releases amylase, lipase and protease that continue digestion of starch and protein.
- the liver releases bile and speeds up the digestion of lipids as it neutrilises acid from the stomach.
What is the fourth stage to the digestive system
-the walls of the small intestine release protease and lipease to continue the breakdown of protein and lipids. as the food molecules are smaller, some are absorbed into the blood stream by active transport or diffusion
What is the fith stage of the digestive system
- the fluid makes its way through the large intestine, where the water is absorbed into the bloodstream
- feeces are released from the body
What are the products of the digestive system used for
- new carbohydrates
- new lipids
- new proteins
- glucose produced is used in respiration
What are enzymes?
-large protein molecules that speed up reactions
What is the active site
-This is where the substrate (molecule breaking down) locks on to
How is the substrate described to attach to the active site?
- like a lock and key
- only some elements are able to break down with the enzymes
What enzyme breaks down proteins?
-protease
What are proteins
-these are long chains of chemicals called ammino acids
What happens when protease breaks down the proteins
-the proteins are broken down into there induvidual acids where they are absobed into the blood stream
What happens to the structure of the proteins when they are absored into the bloodstream.
They are re structured to make human proteins - these are used for growth and repair
What is the structure of starch?
-chains of glucose molecules
What is the enzyme that breaks down carbohydrates?
-carbohydrases
what enzyme breakes down starch specifically
-amylase
What happens when carbohydrates are digested
-simple sugars are produced
Where is amylase found
- saliva
- pancreatic fluid
What is the structure of a lipid
one molecule of glycerol and three molecules of fatty acids
What are lipid molecules digested by?
-lipase
What product is formed when lipids are broken down?
- glycerol
- fatty acids
Where is lipase found?
- pancreatic fluid
- small intestine
Where is bile made and stored
- made in the liver
- stored in the gullbladder
What is the function of bile
- speed up the digestion of lipids
- neutrilise acids
how does bile speed up the digestion of lipids
- it converts small droplets of lipids into larger droplets
- it is said that it emulsifies
- it largly increases the surface area and increases the rate of lipid breakdown by lipase
How does bile neutrilise acids
- bile is very alkiline
- this neutrilises stomach acids creating alkiline conditions in the small intestine
- this increases the rate of digestion by lipase as the enzymes are ment for a more neutral Ph
What are enzymes made of?
Simple proteins
What happens to the activity of the enzyme as the tempreture increases?
- as the temp. inceases, the activity increases as they are moving and colliding more times a second - increases reaction
- the optimum tempreture is the best temp to have an enzyme at as they are most productive.
- as it goes past this, it rapidly decreases as the enzyme starts to become denatured
Where is the optimum tempreture for the enzyme
37 celcius
Why does the enzyme start to decrease in activity?
-beacuse the enzyme starts vibrating, changes shape and becomes denatured - the substrate can’t fit in
What effect does the Ph have on the enzymes
- if the enzymes are too acidic or too alkaline, it rapidly drops to 0 as it becomes de natured
- each enzyme has an optium ph - depending on where it is released and used.
Where are the products of digestion absorbed into the blood stream
in the small intestine thorugh the partially permeable membrane
How is the small intestiene adapted to absorb nutrients
- 5m long - large surface area
- covered with villi - massivly increase the surface area
- have microvilli
- high concentration gradient as there is a large amount of blood flow near villi
- villi have a thin membrane - short diffusion path
- if can’t be done by diffusion, active transport is used.