Biology Mock Exam 2021 Flashcards
Photosynthesis is a ______ reaction used by ______ to make _______ and ________ (products) from ______ _______ and _______ (reactants)
chemical, plants, glucose, oxygen, carbon dioxide, water
Photosynthesis is an e_______ reaction - it uses/takes in _______ from the _________ in order to take place.
Specifically, photosynthesis takes in _______ from the ____. , through the _____ it emits
endothermic, energy, environment
energy, sun, light
The word and symbol equation for Photosynthesis is
_____ ______ + ______ —-> _______ + ________
__ ___ + __ ____ —-> ________ + __ ___
Carbon Dioxide + Water —-> Glucose + Oxygen
6 CO2 + 6 H2O → C6H12O6 + 6 O2
The _____ from the ____ in photosynthesis is absorbed by a green ______ called ________ in the l_____.
________ is found in ________ in ______ cells.
light, sun, pigment, chlorophyll, leaves
Chlorophyll, chloroplasts, plant
The ______- ______ needed for photosynthesis comes from the ___ and enters the leaves through the ________.
carbon-dioxide, air, stomata
W_______ enters the plant through the ____, and is transported to the _____ in the ______.
Water, roots, leaves, xylem
Some of the _______ produced from photosynthesis is used during cellular ________, and some is converted to _______ to be ______.
Some of the ______ is also used to make larger, complex ________ that the plants need to ____ (e.g. Lipids, ______ and more). These make up the organisms _______.
glucose, respiration, starch, stored
Photosynthesis takes place in the __________. These contains the _______ that catalyse ________ in photosynthesis as well as ________, which is a green ______ that absorbs _____.
chloroplasts, enzymes, reactions, chlorophyll, pigment, light
The two stages of photosynthesis are
- _____-_______ stage
- _____-_________ stage
Light-dependent stage
Light-independent stage
The light-dependent stage is the _____ stage of photosynthesis where _____ is used to _____ water into _________ and ________.
The _______ is released as a _____ product and the ________ is carried off into the ________ stage (LID).
This stage requires ______ in order to take place
first, light, split, hydrogen, oxygen
oxygen, waste, hydrogen, second
light
The LID is the _______ stage of photosynthesis. This is when _______ _______ enters the cell which combines with the _________ molecules to form ________.
This stage does not require _____ in order to take place.
second, carbon dioxide, hydrogen, glucose
light
The 3 limiting factors of photosynthesis are
- Amount of ______
- Amount of ______ _______
- __________
Light
Carbon Dioxide
Temperature
Light transfers the ______ needed for photosynthesis.
As light intensity increases, the rate of photosynthesis _______ until up to a ______ point - at this point, light is not a _______ factor - adding more light will make no _______ , so ____ and _______ may be responsible.
energy
increases, certain, limiting, difference/change, CO2 , temperature
It is important to use a _____ meter to get the most _______ results when plotting _____ intensity. Or you’ll have ti use the ______ square law as when distance _______, light intensity _______ .
light, accurate, light. inverse square law, increases, decreases
The formula for inverse square law is
_____ intensity = 1/___
Light intensity = 1/d2
Graph of Light intensity and rate of photosynthesis
Y Axis = ____ of photosynthesis
X Axis = _____ intensity
Graph is a _____ that gradually ______ until a certain _____ where it completely _______ out and becomes _______.
Y Axis = Rate of photosynthesis
X Axis = Light intensity
curve, increases, point, flattens, constant
____ Is one of the substances needed for photosynthesis.
Increasing CO2 will ______ the rate of _________, up till a _______ point where the graph _______ out and becomes ________ - CO2 is no longer a limiting ______, and so _____ and ________ may be responsible.
CO2
increase, photosynthesis, certain, flattens, constant, factor, light, temperature
Graph of level of CO2 (%) and rate of photosynthesis.
Y Axis = ____ of photosynthesis
X Axis = Level of ___ (%)
Graph is a _____ that gradually ______ until a certain _____ where it completely _______ out and becomes _______.
Y Axis = Rate of photosynthesis
X Axis = Level of CO2 (%)
curve, increases, point, flattens, constant
Temperature - If the temp is too low, there will be less _______ between enzymes and _______ which _____ the reaction.
If the temp is too high, the enzymes would have _______ so less ______ can take place which _______ the rate of photosynthesis.
There is an ideal, ______ temperature - this is the temperature at which the rate of _________ is at its ________.
collisions, substrates, slows
denatured, reactions, decreases
optimum, photosynthesis, highest
To summarise
Temp low - Enzymes ____
Temp high - Enzymes ______
Best rate - At _______ temp
slow
denatured
optimum
Enzymes are biological _______ - they ______ __ the rate of _______ reactions in the body.
They _______ reactions in both ______ and _______.
catalysts, speed up, chemical
catalyse, plants, animals
Every enzyme has an ______ site - the part of an enzyme which has a specific ______ which can only _______ a certain ________.
Enzymes usually only work for ___ specific type of ________. - other enzymes will not ___ in the ______ ____ and thus won’t be _______.
active, shape, catalyse, enzyme
one, enzyme, fit, active site, catalysed
Enzymes follow the ____ and ____ model - the ______ ____ shape allows only ____ specific type of _______ to be _______ - only this ______ can fit into the ______ site (like a ____ and a ___!)
lock and key model, active site’s, one, substrate, catalyses, substrate, active site, lock and a key
The 3 factors affect the rate of _______ for enzymes
- _________
- ___
- ________ concentration
reaction
- Temperature
- pH
- Substrate concentration
Increasing temperature at first increases the _______ of enzymes and ________, thus allowing for more enzymes and ________ to ______ and form _______-______ complexes.
energy, substrates, substrates, collide, enzyme-substrate complexes
If it gets too ___, some of the _____ holding the enzyme together ______ - this causes the ______ ____ of the enzyme to _______ (change ______), so the ________ won’t fit anymore.
All enzymes have an _______ temperature at which their rate of _______ is at it’s _______.
hot, bonds, break, active site, denature, shape, substrate
optimum, reaction, highest
Graph of Enzyme rate of _______ and temperature
Shaped like an _______ U shape, with a gradual ________ and then _________.
Y Axis = Rate of _______
X axis = __________
reaction
inverted/upside down, increase, decrease
pH also affects enzymes. If it’s too ____ or too ____, the pH interferes with the _____ holding the _______ together - this causes the enzyme to _______ (_____ ____ changes ______)
All enzymes have an _______ pH at which they ____ work at. It’s often neutral pH __, but not always
high, low, bonds, enzymes, denature (active site changes shape)
optimum, best, pH 7
Graph of Enzyme rate of _______ and pH
Shaped like an _______ U shape, with a gradual ________ and then _________.
X Axis = ___
Y axis = Rate of ________
reaction
inverted/upside down, increase, decrease
X Axis = pH
Y Axis = Rate of reaction
________ concentration also affects the rate of _______ - higher the ________ _______, the _______ the reaction as it’ll be more _______ that an enzyme will meet up and ______ with a ________.
This is only up until a _____ point - there are so many ________ that all ______ ____ are full and so adding more ________ will make no difference.
Substrate, reaction, substrate concentration, faster, common/likely, react, substrate
certain, substrates, active sites, substrates
Graph of Substrate Concentration and rate of reaction
Y Axis = ____ of reaction
X Axis = ________ concentration
Graph is a _____ that gradually ______ until a certain _____ where it completely _______ out and becomes _______.
Y Axis = Rate of reaction
X Axis = Substrate concentration
curve, increases, point, flattens, constant
Light absorption in the leaf happens in the ________ ________ tissue of the leaf.
________ cells are _______-shaped and packed with many __________.
They are arranged ______ together so that a lot of light energy can be _________.
palisade mesophyll
Palisade, column, chloroplasts
closely, absorbed
Cross section of a leaf
Search the image for it
3 features of leaves and their functions
Large _______ ____ - To maximise _____ absorption
Thin - Short _______ for _____-______ to _______ into leaf cells
_______ - A waxy ________ layer which reduces ______ loss, it is ________ to allow light through the leaf
Large Surface Area, light
distance, carbon-dioxide, diffuse
Cuticle, waterproof, water, transparent
The stomata controls ___ ________ in the leaf. Each stoma can be _____ or ______, depending on how _____ its ____ cells are.
gas exchange, open, closed, turgid, guard
The stomata can open and close to
- Regulate ________
- Allow ___ _______
transpiration
gas exchange
Diffusion of CO2, __ and _____ _____ into (or out of) the leaf is greatest when the stomata are ____, during the ____time.
O2, water vapour, open, daytime
The Xylem transports ____ and _______ from the _____ up to other parts of the plant
The Phloem transports _______ and _______ ____ from the ______ and other parts of the plant.
water, minerals, roots
sucrose, amino acids, leaves
The Xylem consists of elongated _____ cells, that are connected ___ to ___ to form continuous _______ (tubes)
dead, end to end, vessels
Xylems vessels
- Contain no _________
- Are ________ to water
- Have tough _____ containing a woody material called _____.
no cytoplasm
impermeable to water
tough walls, lignin
Phloem consist of ______ cells arranged ___ to ___. They contain _______, and this goes through the holes in the _____ _____ from one cell to the ______.
Chemicals such as ________ also move through the plant by _________.
living cells, end to end, cytoplasm, sieve plates, next
pesticides, translocation
Phloem transports _______ and _______ ____ up and _____ the plant - This is called __________.
This happens between where the substances are made (the ______) and where they are used or stored to (the _____).
sucrose, amino acids, down, translocation
source, sink
This means, for example, that sucrose is transported
- from sources in the ____ to sinks in the _____ in spring time
- from sources in the ______ to sinks in the _____ in the summer
root, leaves
leaves, root
Clarification
Translocation is the transport of _______ _______ within a plant
dissolved material
______ bundles are groups of ______ and ______ tissue in a plant
In a leaf, the phloem is usually found closer to the _____ surface of the plant.
Vascular bundle, xylem, phloem
lower
Root
Xylem vessels are _____ and _____, so the _______ bundles are in the ______ of the root to _____ forces that could pull the plant out of the ground.
tough, strong, vascular, centre, resist
Stem
The stem has to resist ________ (squashing) and _______ forces caused by the plant’s ______ and the ____.
The _______ bundles are arranged near the ____ of the stem, with the phloem on the _______, and the xylem on the _______.
compression, bending, weight, wind
vascular, edge, outside, inside
Transpiration is the evaporation of ____ at the surfaces of the ______ _______ cells in leaves, followed by loss of water vapour through the _______.
water, spongy mesophyll, stomata
Water moves through the _____ vessels in a continuous _________ stream
root → ____ → leaf
xylem, transpiration
stem
Transpiration produces a ______ or “pull” on the water in ______ vessels by the ______, Water molecules are _______ (able to ____ together), so water is pulled ___ through the plant.
tension, xylem, leaves, cohesive, stick together, pulled up
The functions of the transpiration stream are
- Transporting _______ ___
- Providing water to keep cells _____ (enlarged and ______ by water) by filling ______ in order to support the planting and stop it ______
- Providing water to ____ cells for __________
- Keeping the leaves cool by _________.
mineral ions
turgid, swollen, vacuoles, wilting
leaf, photosynthesis
evaporation
Rate of transpiration
If the rate of transpiration increases, the rate of _______ of water by the root _______ as well.
transpiration increases, absorption of water increases
Root hair cells BBC
Root hair cells are where most water _______ happens.
They are l___ and ____ so they can penetrate between ____ particles, and they have a large _______ ____ for maximising ________ of water via ________.
water absorption
long and thin, soil particles, large surface area, absorption of water via osmosis
Root hair cells BBC
Water passes from the ____ water to the root hair cell’s _______ by ________.
This happens because the soil water has a higher _________ than the root hair cell _______.
soil water –> root hair cell’s cytoplasm via osmosis
higher concentration, cytoplasm
Plants can only absorb _______ minerals (those that can ______ in water). They absorb minerals dissolved in solution from the soil through their _____ ____ cells.
soluble minerals, dissolved
root hair cells
Minerals cannot be transported via osmosis because this is the transport of ______ only.
Minerals cannot be absorbed by diffusion, because minerals are in very low ___________.
Instead, minerals are absorbed via ______ ________
osmosis - transport of water only
diffusion, minerals in very low concentration
minerals absorbed via active transport
Active transport
The root hair cells have _____ proteins in their ____ ________. These pick up the mineral ___ and move against the ________ gradient. (___ concentration to ____ concentration).
carrier proteins, cell membranes, mineral ions, against concentration gradient, low –> high
Because active transport moves ions ______ the concentration gradient into the ___ ___ cells, _____ is needed.
The energy is supplied in the form of ____.
against, root hair cells, energy is needed
ATP
