b6

Photosynthesis Symbol Equation

6 CO2 + 6H2O → C6H12O6 + 6O2

Root Hair Cell Adaptation

Large surface area, many mitochondria for active transport

Phloem Function

Structure for sucrose transport in plants

Phloem Structure

Living cells arranged end to end. sieve cells with minimal organelles and companion cells. They have pores

how do plants get the co2 required

diffuses from the air into the leaves via stomata

how does water move up the xylem

transpiration moves one up and then the polarity of water attracts the other molecules up

Photosynthesis Word Equation

Carbon dioxide + water → glucose + oxygen

Chloroplast Function

Part of plant cell that absorbs light for photosynthesis

Photosynthesis Reaction Type

Endothermic

Xylem Function

Structure for water and mineral transport in plants

Xylem Structure

Lignified dead cells with a thick wall

effect of temp on photosynthesis

as temp increases rate of photosynthesis does as well as the enzymes have more KE and are more likely to collide. After the optimum, the enzymes denature and it decreases the rate

effect of light intensity on photosynthesis

as light intensity increases, so does rate until the optimum when it plateaus as something else is limiting

effect of carbon dioxide on photosynthesis

as CO2 increases, so does rate until the optimum when it plateaus as something else is limiting

what makes starch a useful long term storage molecule

can be easily broken down when needed, is compact, insoluble in water

uses of glucose

cellular respiration, make cellulose, make starch to store glucose, make amino acids, make lipids to store energy

why could plants produce insufficient chlorophyll

have a disease like tobacco mosaic virus or lack required nutrients

what does it mean when the guard cells become turgid

they open the stomata

what does it mean when the guard cells become flaccid

they close the stomata

order of leaf structure

waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, lower epidermis

what are the reactants for an experiment testing how light intensity affects photosynthesis rates

pondweed, water, sodium hydrogencarbonate

investigating photosynthesis practical

put pondweed , water and sodium hydrogen carbonate in a test tube with a gas syringe attached

place lamp 20cm away and measure gas produced in 5 minutes

repeat with lamp further away

light intensity formula

1 / d²

what are the units for light intensity

arbitrary units ( a.u )

what do the palisade and spongy mesophyll do

photosynthesis

what does the spongy mesophyll also do

aid gas exchange due to spaces between cells

what are nitrates needed for and what is a deficiency symptom

making proteins, stunted growth

what are magnesium ions needed for and what is a deficiency symptom

making chlorophyll, yellow leave

difference between xylem and phloem for direction of travel

xylem can only transport water upwards. The phloem can travel up and down

what does the waxy cuticle do

reduce water loss by evaporation

translocation

movement of dissolved sugars from the leaves to rest of plant via phloem

transpiration

movement of water up a plant driven by evaporation through stomata

how does water move up the xylem

water evaporates out the leaf via the stomata and the polarity of water molecules drags up the water molecules up the chain.

factors affecting rate of transpiration

air movement, humidity , light intensity, temperature

how does high air movement affect transpiration and why

high air movement means water vapour is removed from the air surrounding the leaf which creates a concentration gradient increasing water loss

how does high humidity affect transpiration and why

high humidity decreases transpiration rate as the concentration gradient is weaker

how does high light intensity affect transpiration and why

high light intensity means guard cells open so more water loss

how does high temperature affect transpiration rate

particles have more kinetic energy to evaporate and diffuse away faster

investigating transpiration experiment

set up potomoter
remove tube and insert it into beaker to create a bubble
measure how far the bubble travels in 10 minutes

what Is used to measure transpiration

potometer

formula for transpiration rate

distance travelled by bubble / time

Ficks law for diffusion

surface area x concentration gradient / diffusion distance

xerophytic plant adaptations to prevent water loss

thick waxy cuticle , small leaves with smaller surface area, less stomata that only open at night , sunken stomata, curled leaves

how do sunken stomata prevent water loss

reduce air flow

how are plants adapted for gas exchange

waxy cuticle, stomata, thin and flat leaves, spongy mesophyll

how do thin and flat leaves aid gas exchange

short diffusion distance for CO2

how are leaves adapted for photosynthesis

broad leaves for large surface area for light, transparent upper epidermis to let in light , xylem and phloem, stomata

auxins

plant hormones that are released at roots or shoots and affect growth

phototropism

growth in response to light

gravitropism / geotropism

growth in response to gravity

Auxins effect on growth at roots and shoots

inhibits growth at roots, stimulates growth at shoots

shoots are -

positively phototropic and negatively geotropic

roots are -

negatively phototropic, positively geotropic

investigating phototropism

set up seeds in a Petri dish . Control light intensity, temp, water and CO2. Position light at different directions. Plants will grow towards the light

how do plants grow towards light

auxins are released at the darker side of the shoot. it stimulates growth of that side so the plant bends towards the light

how do roots grow in gravity direction

auxins are released in lower side of root. It inhibits growth on the lower side so the top grows more. The root will grow downwards

auxins use commercially

rooting powder to grow cuttings, selective weedkiller

how can auxins be used as selective weed killer

they are absorbed by broad leaved plants due to large surface area. They cause excess growth so the plant dies

gibberellins function

seed germination

gibberellins use commercially

induce fruit and flower formation , make seedless fruit grow but not the seeds

ethene function and use

ethene ripens fruit

how do smaller leaves help prevent water loss for plants in dry arid conditions

few and sunken stomata , thick waxy cuticle , needle shaped or small leaves , hairs around stomata

how can curled leaves prevent water loss

it reduces exposure to wind and sunlight to decrease transpiration

algal balls experiment

place algal balls in a bottle with water and hydrogen carbonate indicator. Place bottle at different distances from the lamp. As light intensity increases , the rate of photosynthesis also increases meaning there is less carbon dioxide meaning the solution is more alkaline .

how does translocation transport sugars. steps

source cell turns glucose produced from photosynthesis into sucrose
it enters the companion cell via active transport
it diffuses into the sieve tube element as water diffuses in via osmosis
sucrose dissolves in water and the solution moves down the phloem
sucrose diffuses into companion cell and then into sink cell to be stored as glucose
water diffuses back by osmosis

source cell

where glucose is made

sink cell

where glucose is stored