B2.2 Organisms and Energyy Flashcards
How do glucose and oxygen get to the cells for respiration?
Glucose and oxygen is carried by the blood around the body. The blood also carries away the waste carbon dioxide. These substances move between respiring cells and the capillaries through diffusion. Diffusion happens when particles move from an area where they are in a high concentration to an area where they are in a low concentration. They are diffused over a concentration gradient.
How does the concentration gradient remain constant in respiring cells?
Oxygen and glucose levels fall in cells, and oxygen and glucose diffuse from blood to cells.
Carbon dioxide levels rise in cells, and diffused out into the capillaries.
Describe the gas exchange.
Kung tissue is made up of alveoli (tiny air sacs). These are surrounded by the capillaries. Oxygen that moves into the body through the lungs, diffuses out of them into the capillaries. Carbon dioxide diffuses into the alveoli and out of the lungs. This movement of gases is called the gas exchange.
Why does your heart rate increase during exercise?
The more active a cell is, the more energy it needs so respiration has to happen at an increased rate. This is because the muscles use up the oxygen more quickly, so the blood supply to musicales must increase.
What is the formula for cardiac output?
Cardiac output= stroke volume x heart rate.
Why does the rate at which we breathe increase during exercise?
An increase of blood supply is of limited use without oxygen, so we need to increase our breath rate.
Give the anaerobic respiration chemical equation.
Glucose—> lactic acid+energy. This happens alongside aerobic respiration so that we do not rely solely upon oxygen for energy.
Explain EPOC.
After intense exercise, lactic acid needs to be broken down into carbon dioxide and water using oxygen. This means that after exercise excess oxygen is needed to break down the lactic acid. This oxygen is obtained by maintaining a high breathing rate and heart rate after exercise. The time taken for them to decrease to normal is called the recovery time.
What is starch?
Starch is a simple carbohydrate which plants can use to store glucose in.
Give the photosynthesis reaction
Carbon dioxide+water—->glucose+oxygen
Why do plants photosynthesise?
Hey do it to produce their own glucose for respiration because they do not eat anything.
Who does chlorophyll help with photosynthesis?
Chlorophyll is stored inside the chloroplasts. It is important for photosynthesis, because this green substance, is what absorbs light for photosynthesis. Chlorophyll transfers the light energy into the stored chemical energy in glucose.
How does the large surface area help with photosynthesis?
Leaves are flat and large to absorb as much light as possible for photosynthesis.
How do the stomata help with photosynthesis?
On the underside of the lead, tiny spores called stomata open in response to light, allowing carbon dioxide to diffuse from the atmosphere into the plant. The oxygen produced can also diffuse out of the stomata and the water can evaporate.
How does the large surface area to volume ratio help with photosynthesis?
The air spaces inside the cell give it a large surface area to volume ratio which makes gas exchange more efficient
How does light intensity affect the rate of photosynthesis?
In dim light a plant will photosynthesis slowly because it will not relieve enough light energy for photosynthesis.
How does carbon dioxide affect the rate of photosynthesis?
In order for photosynthesis to happen at a fast rate, their needs to be an ample supply of carbon dioxide in order for photosynthesis to occur.
How does the temperature affect the rate of photosynthesis?
Temperature affect the rate at which the enzymes work, so in order for photosynthesis to happen effectively, the temperature needs to be optimum for he enzymes.
What do the root hair cells do?
The root hair cells have long thin extensions that reach into the surrounding soil, providing a large surface area for substances to enter the cell.
How does water Exeter the root hair cells?
Water enters the root hair cells through osmosis. In this process water moves across a partially permeable membrane, from an area where it is in high concentration to an are where it is in lower concentration.
What is active transport?
Roots can absorbs nitrates and other substances dissolved in soil, even if the concentration is higher in the plant than in the soil water. Absorbing particles against a concentration gradient is called active transport.
How is water transported around plants?
Once the after and minerals have entered the plant through the roots, they need to get up to the plant’s tissues. Xylem a transport the water, and they are specialised tissues formed from dead hollow cells which also give support to the plant. The glucose made by the leaves is converted into sucrose and transported to other parts of the plant through the phloem- strands of living cell tissue.
What is transpiration?
Water is evaporated form the surface of the cells inside the leaves, and moves out through diffusion. This maintains a concentration gradient, so more water evaporates and diffuses out of the leaf. The loss of water pulls the water and dissolved mineral salts through the xylem. Factors which increase evaporation will also increase transpiration.
What is respiration?
Organisms produce energy in order for reactions to take place inside the cells. This is respiration:
Glucose+oxygen—->carbon dioxide+water+energy.
This is aerobic respiration.
