plants

Question 1

how do plant cells differ to animal cells?

Answer 1

cell walls need to be tough but not rigid
have chloroplasts and vacuoles

Question 2

what are vacuoles?

Answer 2

large fluid filled compartments that helps the cell manage osmotic pressure

Question 3

draw the structure of a plant cell

Answer 3

check slide 13, lecture 4

Question 4

what do chloroplasts do?

Answer 4

harvest sunlight to synthesise carbohydrates from atmospheric CO2 and water and deliver the products to the host cell as food

Question 5

draw the structure of a mitochondria

Answer 5

check slide 14, lecture 4

Question 6

draw structure of a chloroplast

Answer 6

check slide 14, lecture 4

Question 7

how do chloroplasts differ to mitochondria?

Answer 7

has thylakoid membrane and space

Question 8

how were chloroplasts thought to have originated?

Answer 8

an early eukaryotic cell that already possessed a mitochondria engulfed a photosynthetic bacterium and retained it via symbiosis

Question 9

do mitochondria have their own genome? what about chloroplasts?

Answer 9

both do

Question 10

what is phagocytosis?

Answer 10

ability to engulf cells

Question 11

why can plant cells no longer undergo phagocytosis and change shape?

Answer 11

it doesn’t need to chase after prey due to chloroplasts

Question 12

what types of cycles do chloroplasts have?

Answer 12

light and dark

Question 13

what are the two categories of reactions that occur during photosynthesis?

Answer 13

photosynthetic electron transfer
carbon fixation

Question 14

is photosynthetic electron transfer light or dark reaction?

Answer 14

light

Question 15

is carbon fixation reaction light or dark cycle?

Answer 15

dark

Question 16

what happens in photosynthetic electron transfer?

Answer 16

photon of light knocks an electron out of chlorophyll
electron moves along electron transport chains (PSII and PSI)
during chain, some of the energy released by energy transfer is used to pump protons which creates a gradient across thylakoid membrane
gradient used by ATP synthase to drive ATP synthesis
electrons are loaded with protons onto NADP+, reducing it to NADPH

Question 17

What does PSI and PSII stand for?

Answer 17

photosystem 1 and 2

Question 18

how does carbon fixation reaction work?

Answer 18

ATP and NADPH produced by light reactions serve as energy and reducing power to drive conversion of CO2 to carbohydrate

Question 19

where do dark reactions occur?

Answer 19

stroma of chloroplast

Question 20

what is produced in carbon fixation reaction, where does it go and what is it used for?

Answer 20

simple sugar produced
exported to cytosol
used to produce sucrose and other metabolites in leaves of plant

Question 21

does carbon fixation reaction need sunlight?

Answer 21

no

Question 22

what are the cell walls like in plants?

Answer 22

tough but not rigid

Question 23

what happens to a plant cell if their cell wall is stripped off?

Answer 23

easily ruptured and extremely vulnerable to osmotic pressure

Question 24

why does the cytoskeleton have almost no tensile strength in plants?

Answer 24

lacks the tension bearing structures found in animal cells

Question 25

where do plant cell walls derive their tensile strength from?

Answer 25

long fibres oriented along the lines of stress

Question 26

what are the long fibres made of in higher plants?

Answer 26

cellulose

Question 27

what is cellulose?

Answer 27

a polysaccharide

Question 28

what is the most abundant macromolecule on earth?

Answer 28

cellulose

Question 29

draw the molecular structure of cellulose

Answer 29

research answer

Question 30

what is the structure of cellulose like in cell walls? what does this mean?

Answer 30

forms microfibrils interwoven with other polysaccharides and some structural proteins bonded together structure resists both compression and tension

Question 31

what is the structure of the cell wall like in woody tissue, and what does this mean?

Answer 31

highly cross linked network of lignin is deposited in the matrix more rigid and waterproof

Question 32

why does turgor pressure form in plant cell wall and what does it cause?

Answer 32

as a result of osmotic imbalance between plant cell interior and surroundings turgor pressure drives cell growth

Question 33

what happens to plant cell walls when cell growth stops?

Answer 33

wall no longer needs to expand so a more rigid secondary wall is often produced