B2.2 Organisms and energy Flashcards
What is the word equation for aerobic respiration?
Glucose + oxygen → carbon dioxide + water ( + energy)
What is the equation for anaerobic respiration?
Glucose → lactic acid ( + energy)
What is respiration?
A series of reactions in all living cells where glucose is broken down to produce energy
What happens to the energy requirements of cells when they become more active?
It increases
What happens to the number of particles as you go down a concentration gradient?
It decreases
What process do capillaries use to move substances from the blood into and out of cells?
Diffusion
What are capillaries?
Tiny blood vessels with thin walls that allow the diffusion of substances into and out of the blood
What is diffusion?
The movement of particles from an area of high concentration to an area of low concentration
What happens to levels of glucose and oxygen as cells respire?
They decrease
What are alveoli?
Tiny air sacs found in lung tissue
What is gas exchange?
The exchange of one gas into the bloodstream for another
How thick are the cell walls of a capillary?
One cell wide
How thick is the cell wall of an alveolus?
One cell wide
What is a pulse?
A surge of blood in the arteries from a heart beat
What is stroke volume?
The volume of blood pumped out of the heart at each beat
What is cardiac output?
The volume of blood circulated by the heart in a given time
What is heart rate?
The amount of beats the heart makes
How do you calculate cardiac output?
Stroke volume x heart rate
What is anaerobic respiration?
Respiration that doesn’t require oxygen
What does broken down lactic acid produce?
Carbon dioxide and water
What substance does lactic acid need to use in order to break down?
Oxygen
What does EPOC stand for?
Excess post-exercise oxygen consumption
What is EPOC?
Period of time after exercise where there is an increased need for oxygen for things such as lactic acid break down and cell repair
Why do people still have a high breathing and heart rate for a few minutes after exercise?
To get more oxygen for the oxygen debt (EPOC)
What is recovery time?
The time taken for the pulse rate to return to normal after exercise
What is starch?
A carbohydrate in which thousands of glucose molecules are joined together
What is released when starch is broken down during digestion?
Glucose
What process do plants use to produce glucose?
Photosynthesis
What do plants store glucose as?
Starch
In what part of a plant does photosynthesis occur?
The chloroplasts
What substance absorbs light for photosynthesis in plants?
Chlorophyll
What adaptions do leaves have in order to increase the amount of light energy they absorb?
The leaves are broad and flat to increase surface area
When do stomata open?
In response to light
What are stomata?
Microscopic pores on the undersides of leaves
What do stomata do?
- allow carbon dioxide and oxygen to diffuse into and out of the plant
- allow some water produced from respiration to evaporate from the surface
How do the large air spaces in leaves make the cells more efficient at gas exchange?
It gives them a larger surface area to volume ratio
What affects the rate at which photosynthesis takes place?
- carbon dioxide levels
- water
- temperature
- light levels
What is a limiting factor?
A single factor that when in short supply can limit the rate of a process
What is the maximum rate of a reaction controlled by?
The limiting factor
What do roots do?
- anchor the plant into the ground
- take up water and mineral salts from the soil
What is the name of the specialised cells that increase the surface area of a root?
Root hair cells
What form of transport does water entering root hair cells use?
Osmosis
What is osmosis?
The diffusion of water from an area of high concentration to low concentration across a partially permeable membrane
What is active transport?
The absorption of particles against a concentration gradient
What type of cells do the veins of a plant contain?
Xylem and phloem cells
What do xylem cells do?
- transport water and dissolved mineral salts to tissues in the plant
- give support to the plant
Are xylem or phloem cells dead?
Xylem
How are xylem cells specialised for their purpose?
They are long and die to form hollow tubes
What do phloem cells do?
Transport sucrose to different parts of a plant
Where is the main area where photosynthesis in a plant occurs?
The palisade layer
What is transpiration?
The evaporation of water vapour from the surface of a plant
What does a potometer do?
Measure the rate of water uptake by a plant
What is an organism’s environment?
It’s surroundings
What is biodiversity?
The variety of species present within a given area
What is an ecosystem?
An area where all the organisms form a stable relationship that doesn’t need input from outside to help them remain stable
What is a habitat?
The place where an organism usually lives
What are the different sampling techniques used to find the distribution of organisms in an ecosystem?
- pooters
- sweep nets/pond nets
- pitfall traps
- quadrats
How do you obtain a random sample of an area?
You divide the area into squares and then number them. A computer generates a random number and you use that square
What is sampling?
Looking at a small portion of an area or population
What is a pooter used to catch?
Small invertebrates
How are population sizes estimated?
A random sample is collected and then the values are scaled up to fit the whole area
What is systematic sampling?
Sampling where quadrats are placed along regular intervals on a line
What can affect the distribution of different species of plants?
- light intensity
- soil
- tempearture
- water pH
What is the distribution of an organism?
The places in which it can be found in a certain area
