GCSE Revision 4/7 Flashcards
Photosynthesis equation
Carbon dioxide + water —–(light energy)—–> glucose + oxygen
6CO2 +6H2O ———> C6H12O6 + 6O2
What type of reaction is photosynthesis
Endothermic
Process for photosynthesis (3)
CO2 is takin in by the leaves, and water is taken up by the roots
The chlorophyll traps the light energy needed for photosynthesis
This energy is used to convert the CO2 and water into glucose
What happens after photosynthesis (2)
Oxygen is released as a by-product
Some of the glucose is converted into insoluble starch for storage
How are leaves adapted for photosynthesis (5)
Broad and flat so they have a large surface area
Thin so the diffusion path is short
Guard cells open the stomata so that gases can diffuse in and out of the spaces inside the leaves
The photosynthetic cells in the leaves contain chlorophyll
Veins contain xylem which bring water to the leaves, and phloem which takes glucose away
Rate of photosynthesis factors (4)
Light intensity
Temperature
Amount of CO2 present
Variegated leaves (white spots)
Light intensity equation
light intensity ∝ 1/distance^2
Uses of glucose (4)
Converted into starch/fats/oils for storage
Used for respiration
Used to produce cellulose in cell walls
Used to produce proteins
How do farmers make greenhouses better for photosynthesis to occur (4)
Maintain temperature
Increase CO2 levels
Artificial lighting to extend the hours
Levels of nutrients are monitored
Hydroponics
Plants grown in a solution of mineral ions instead of soil
What type of reaction is anaerobic respiration
Exothermic
Equation for aerobic respiration
Reverse of photosynthesis
How does the body use the energy transferred due to aerobic respiration
Build larger molecules from smaller ones
Enable muscle contraction
Maintain a constant body temperature
Move materials (eg mineral ions) into cells against a concentration gradient (active transport)
Build sugars, nitrates etc intro amino acids and then proteins in plants
How to detect aerobic respiration occurring (2)
Limewater turns from transparent to cloudy
Temperature increases
How does the body increase the rate at which reactants are brought and waste is removed for aerobic respiration (3)
Heart rate increases
blood vessels supplying the muscles dilate
Breathing rate and depth of each breath increase
Muscles store glucose as glycogen, which can be converted back during exercise
Anaerobic respiration equation
glucose——>lactic acid
C6H12O6——>2C3H6O3
Oxygen debt
When exercise has finished, the lactic acid must be completely broken down, during which your body must take in extra oxygen for a while after exercise
Oxygen debt equation
Lactic acid + oxygen ——–> carbon dioxide + water
C3H6O3 + 3O2 ——–> 3CO2 + 3H2O
Anaerobic respiration in plants equation
Glucose ——-> ethanol + carbon dioxide
C6H12O6 ——-> 2C2H5OH + 2CO2
What is anaerobic respiration in yeast cells called
Fermentation
What do bacteria used in yoghurt production produce
Lactic acid
What are some metabolic reactions (6)
Glucose to starch, glycogen or cellulose
Fatty acids and glycerol to lipids
Glucose and nitrate ions to amino acids
Amino acids to proteins
Reactions of respiration/photosynthesis
Breakdown of excess proteins to form urea
How does the liver break down/ remove proteins (3)
Amino acids are deaminated in the liver which forms ammonia
Ammonia is then converted to urea
Urea passes in the blood to the kidneys and is excreted in the urine
How does the liver deal with ethanol
Ethanol is detoxified in the liver and then transported to the kidneys to be excreted
How does the liver deal with red blood cells
Old red blood cells are broken down and the iron is stored to make new red blood cells
How does the lived deal with lactic acid
The liver converts lactic acid to glucose. Excess glucose can be stored as glycogen in the liver
