Biology Term 1 Flashcards
What is diffusion?
Diffusion is the movement of particles from an area of high concentration to an area of low concentration, down a concentration gradient.
What is concentration?
Concentration is a measurement of how much solute is dissolved in a given
volume of solvent.
What is water potential and what lowers water potential?
The ‘potential’ (ability) for water to move freely. Solutes prevent water from moving freely.
What is osmosis?
Osmosis is the diffusion of water from a more dilute solution to a more concentrated solution, across a partially permeable membrane
Isotonic
When the concentration of solutes in the solution outside the cell is the same as the concentration inside the cell. The solution is isotonic to the cell
Hypertonic
When the concentration of solutes is higher outside the cell than inside, the solution outside is hypertonic to the cell
Plasmolysis
When the permanent vacuole of a plant cell looses water through osmosis and as a result, due to a lack of pressure the cell membrane pulls away from the cell wall
What does turgor pressure do
Helps a plant keep rigid structure
What is active transport?
Active transport is the process of cells transporting substances across a membrane AGAINST the concentration gradient moving molecules or ions from an area of low concentration to one of high concentration.
Why is active transport so important?
Active transport allow minerals and ions in the soil that are usually in very dilute solutions (more dilute than the solution in plant root cells) to be absorbed even though its against the concentration gradient.
What is used to test for sugar?
Benedict’s solution
What is used to test for starch?
Iodine
What is used to test for lipids?
Ethanol
What is used to test for Protein?
Biuret Reagant
What is the colour change of Iodine if starch is present?
Yellow-red to Blue-Black
What forms if the test for lipids is positive
A cloudy white layer
What colour will Benedict’s solution turn if there is sugar present?
Blue to Brick Red
What colour will the blue Biuret Reagent turn if protein is present?
Purple
Which test do you have to heat in a water bath to gain results
Benedict’s solution in test for sugar
Describe how you test for starch
Place small amounts of food on spotting tiles
Add a few drops of iodine to each one
Iodine will turn blue-black if starch is present
Describe how you test for Sugar
Place small amounts of food in test tubes.
Add enough Benedict’s solution to cover them
Agitate slightly
Place in warm water bath for 10mins
Sugar is present if solution has turned Brick Red
Name the 3 different enzymes and what nutrient they break down
Carbohydrates- carbohydrase
Protein-protase
Lipids-lipase
What are carbohydrates broken down into
Sugars
What are proteins broken down into?
Amino acids
What are lipids broken down into
Fatty acids and glycerol
Where is carbohydrase found
Mouth/saliva and the small intestine
Where is lipase found
Small intestine
Where is protase found
Produced in stomach, small intestine, pancreas but breakdown in stomach and small intestine
Why does temperature affect rate of reactivity
When you add heat energy, enzymes and molecules collide more. This increases rate of reactivity until a certain point where vibrations are too forceful that the molecule cant fit into the active site of the enzyme, they become denatured
What are enzymes made of
Special proteins
