CB6 - Plant Structures and Their Functions Flashcards
What is the word equation for photosynthesis?
carbon dioxide + water –> oxygen + glucose
What is the symbol equation for photosynthesis
CO2 + H2O –> O2 + C6-H12-O6
What is biomass?
Materials of an organism without water
What are producers?
Organisms that produce their own food
What is photosynthesis?
A series of chemical reactions catalysed by enzymes
What is an exothermic reaction?
A reaction that releases energy
What is an exothermic reaction?
A reaction that releases energy
What is an endothermic reaction?
A reaction that absorbs energy
Is photosynthesis endo or exothermic?
Endothermic
Why is photosynthesis endothermic?
The products have more energy than the reactants
What is found in a plant cell? (8)
nucleus
vacuole
cell wall
cell membrane
chloroplast
cytoplasm
mitochondria
ribosome
What is found in a plant cell?
nucleus
vacuole
cell wall
cell membrane
chloroplast
cytoplasm
mitochondria
ribosome
What is the function of the nucleus?
Controls the cell
What is the function of the vacuole?
Stores sap
What is the function of the cell wall?
Structure and support
What is the function of the cell membrane?
Lets things in and out of the cell
What is the function of the ribosomes?
Makes proteins
What is the function of the chloroplast?
Photosynthesis
What is the function of the cytoplasm?
Where chemical reactions take place
What is the function of the mitochondria?
Aerobic respiration
Where does photosynthesis take place in the cell?
Chloroplasts
What is the function of chlorophyll?
Trap the energy transferred by light.
What is the polymer of glucose called?
Starch
What is the starch used for?
Some broken down into sucrose
Glucose for respiration
What are the factors that affect photosynthesis?
Carbon dioxide concentration
Temperature
Light intensity
What is a limiting factor?
A factor that prevents a rate increasing
Why is temperature a limiting factor?
Enzymes are more active at higher temperatures
What is the formula for inverse square law?
light = O-intensity x O-distance^2
intensity —————————————–
N-distance^2
What parts make up a leaf? (7)
waxy cuticle
upper epidermis
palisade mesophyll
spongy mesophyll
vascular bundle
lower epidermis
waxy cuticle
Why are leaves broad and flat?
Larger surface area
What do palisade cells contain?
Chloroplast
Why are the palisade cells at the top of the leaf?
Maximise photosynthesis
What is the function of the waxy cuticle?
A waterproof layer that prevents water loss out the leaf
What is the upper epidermis?
Layers of cells with no nucleus that allows light to pass through
Why are there air spaces in the leaf?
For diffusion of gases
What is contained in the vascular bundle?
Xylem
Phloem
What are stomata?
Microscopic pores at the bottom of the leaf
What are guard cells?
Specialised cells that open and close the stomata
What happens to stomata during the day?
Water flows into the guard cells which become rigid and open
Carbon dioxide diffuses in the cell
Oxygen diffuses out of the cell
What happens to stomata during the night?
Water flows out the guard cells which become flaccid and closed
No gases can diffuse
Water cannot leave
Why are the stomata at the bottom of the leaf?
Water leaves through the stomata via evaporation
If the stomata were at the top of the leaf the water would evaporated to quickly so the plant wouldn’t get water
What is osmosis?
The movement of water molecules through a semi-permeable membrane down a concentration gradient.
What is diffusion?
Movement from an area of high concentration to an area of low concentration (down a concentration gradient)
What is active transport?
The moment of particles up a concentration gradient using energy.
What is the water absorbed by plant roots used for?
Carrying dissolve mineral ions
Keeping cells ridgid
Cooling the leaves
Photosynthesis
How is a root hair cell adapted to its function?
Large surface area
Thin cell walls
How do these adaptions help? (Root hair cells)
LSA - water and mineral ions can be quickly absorbed
Thin - easy for water and minerals to pass through
What is transpiration?
Flow of water and dissolved minerals from roots and out of the leaves
What is translocation?
The active transport of sucrose and amino acids from leaves up and down the stem.
How does the sieve tube help phloem move dissolved sugar?
It transports the sugar up and down the plant (continuous tube)
How do the sieve plates help phloem move dissolved sugar?
Allows sugar to move up and down the plant
How do the companion cells help phloem move dissolved sugar?
They contain lots of mitochondria for energy for the active transport of pumping sugar up and down the stem.
How are the cytoplasm’s of phloem adapted to maximise the flow of sugar?
They are narrow
What are phloem made up of?
Living cells
What are xylem made up of?
Dead cells
How do the no end walls help xylem move water?
Forms a continuous hollow tube.
How do the lignin spirals help xylem move water?
The strengthen and support the plant
How do the pits help xylem move water?
They let water out through osmosis
