Unit 3,4,5,6 Flashcards
What is diffusion
The net movement of molecules or ions from an area of high concentration to an area of low concentration down the concentration gradient
What factors affect the rate of diffusion
Temperature
Distance molecule travels
What is osmosis
Osmosis is the net flow of free water molecules down a water potential through a partially-permeable membrane
What is active transport
Active transport is the movement of ions or molecules in or out of a cell through the cell membrane against a concentration gradient
What does a balanced diet contain
Carbohydrates Proteins Fats Vitamins Fiber Minerals Water
Carbohydrates contain what
Carbon
Hydrogen
Oxygen
What are Proteins
Proteins are long chain molecules made up of smaller molecules called amino acids
The structure of DNA
Double Helix
Formed by pairs of bases
4 different types of bases A-T C-G
What does DNA stand for
Deoxyribonucleic acid
Enzymes are biological catalysts:
Increase the rate of chemical reaction
Without being used up
Example of an enzyme
Catalase is found in plant cells. It breaks down toxic hydrogen peroxide into oxygen and water
Enzymes properties
They are all proteins Each enzyme catalyses one reaction They can be used again and again They are influenced by PH They are influenced by temperature
The process of Photosynthesis
Carbon dioxide + water —- sunlight and chlorophyll —- glucose + oxygen
From where does the leave get the water for photosynthesis
From the soil through the roots
Needs to go to the leave
From where does the leave get CO2
Comes from the air
Plant takes it up through stomata
The requirements for photosynthesis
Light
Chlorphyll
Carbon dioxide
Water
For what is glucose used in the plant
Glucose is used by plants for energy and to make other substances like cellulose and starch
Rate of photosyntehsis: As the temperature increases
The rate of photosynthesis decreases because enzymes get denatured
Rate of photosynthesis: As the rate carbon dioxide increases
The rate of photosynthesis increases to a certain point
Limiting factors: Light intensity
Light intensity influences the rate of photosynthesis. If the light intensity is low, it does not matter if the plant has lots of carbon, it will not photosynthesize because it doesn’t have enough light
Limiting factor: CO2 Concentration
If there is not enough CO2 the plant won’t photosynthesize
Limiting factor: Temperature
The rate at which enzymes work is affected by temperature
