photosynthesis Flashcards
What is photosynthesis?
The process in which plants make glucose and oxygen for food
What is respiration?
The production of energy with the intake of oxygen and the release of carbon dioxide.
What are food chains?
Food chains display the transfer of energy between living organisms.
Give an example of a producer in a food chain
Plants. They are able to produce their own food from sunlight by photosynthesis.
What is biomass?
The amount that makes a living organism
What is an endothermic reaction?
When energy is taken in
What is an exothermic reaction?
When energy is given out in the form of heat.
List the order of the things that make the structure of a leaf. Top to bottom.
Waxy cuticle Upper epidermis Palisade layer/mesophyll layer Spongy mesophyll layer Lower epidermis Guard cell Stoma Air spaces Waxy cuticle
What is the function of a waxy cuticle?
This is found at the top and bottom of a leaf cell. Layer of protection that helps water drainage so leaf won’t mold
What is the function of an upper epidermis?
Allowed sunlight to pass through so photosynthesis can take place.
What is the function of the palisade layer?
Where photosynthesis can take place.
What is the function of the spongy layer?
Allows exchange of gases. Carbon dioxide comes in and diffuses here.
What is the function of the lower epidermis?
The stomata allow gases in and out of the leaf
what is the respiration equation?
glucose + oxygen → carbon dioxide + water + ATP
C(6)H(12)0(6) + 6O(2) → 6CO(2) + 6H(2)O + ATP
what is the photosynthesis equation?
carbon dioxide + water →(chlorophyll) sugar + oxygen
6CO(2) + 6H(2)O → C(6)H(12)O(6) +6O(2)
what is the function of the guard cells?
these open and close. they open when there is lots of water and close when there is not enough
what are the products of photosynthesis?
plants make glucose during photosynthesis. they convert this into other products used by the plant such as
- starch in food store
- lipids or oils
- proteins for growth and hormones
what are the limiting factors of photosynthesis and what effect do these have on the rate of reaction.
- light intensity
- CO2 concentration
- temperature
if there is not enough of 1 limiting factor, the rate of reaction cannot increase
what is the effect of light intensity?
light intensity is a key addition that plants need. as the light intensity increases, the rate if photosynthesis increases
what is the effect of temperature?
all enzyme reactions require heat energy. an increase in temperature will increase the rate of photosynthesis this is until the reaction reaches its optimum temperature before the enzyme denatures
what is the effect of CO2 concentration?
carbon dioxide is needed by plants to make glucose. as co2 increases the rate of reaction increases.
what do plants exchange with their surroundings?
water
minerals
co2
oxygen
how is each surface adapted for exchange?
large surface area
root hair cells
stomata
air spaces in leaf
where does exchange take place?
roots
leaves
features of the rooots
- root hair cells increase the surface area
- they collect water molecules via diffusion
- doesn’t have chlorophyll because it is underground
features of the leaves
- large surface area
- thin to give short diffusion distance
- air spaces store gases
- water exits through stomata via diffusiom
what is transpiration
the loss of water from the leaves
if it is warmer what happens to transpiration?
the process is faster because thermal energy is converted into kinetic energy and so the particles move faster
if it is windier what happens to transpiration?
tjhe process is faster as evaporated water is removed from the surface of the leaf maintaining the concentration gradient
if it is drier, what happens to transpiration?
process is faster because there is a greater concentration dradient
if it is dark waht happens to transpiration?
process is slower because the stomata close in the dark
function of xylem
transports minerals and water. usually dead
function of phloem
transports sucrose. made up of living tissue
how can a plant prevent how much water is lost?
- close itself up (less surface area)
- lose leaves
- close stomata
- less stomata
- sunken stomata
- waxy cuticle
- hairs to trap water
what are xerophytes?
plant living in warm environment
what do plant hormones allow the plant to do?
- grow towards the hugs
- roots respond to water
- plant has to know which way it grows
what is phototropism
reaction of a plant to light. light is needed for photosynthesis so plants grow towards it
what is geotropsim
reaction of a plant to gravity roots grow towards gravty
what is hydrotropism
reaction of plant to water. roots grown outwards and downwards to find water
What is oxin?
Plant hormones made at the tip of shoots and are distributed around the plant. Used in weed killers and it makes the plant grow fast sometimes too fast and then it dies.
What is horticulture?
Low scale growing plants and flowers
What is agriculture?
Farming larger scale than horticulture
What is gibberellin?
Hormone that stimulates plant germination
Define germination
Growing of a plant
What is ethane
Hormone produced by plants/fruits to ripen. People take ethane out then put it back in when it is being sold in a shop
What is controlled by plant hormones?
Growth Ripening Leaves change colour Leaves fall off Seed germination
