Term
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Definition
-Movement
-Respiration
-Sensitivity
-Growth
-Reproduction
-Excretion
-Nutrition |
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Term
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Definition
| An enzyme is a protein that speeds up chemical reactions in our cells. |
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Term
| When do enzymes work their best? |
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Definition
| When they reach optimum temperature. |
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Term
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Definition
| Maintaining a constant internal environment. |
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Term
| How does temperature affect enzymes? |
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Definition
| As temperature increases, so does the rate of chemical reactions. More heat causes the enzymes to have more energy, causing more successful collisions between enzymes and substrate molecules. If there is too much heat, then enzymes will start to become denatured and will not work. |
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Term
| Describe the lock and key model. |
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Definition
| Enzymes have an active site in which only substrate molecules with the correct shape will be able to fit into. |
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Term
| What can cause an enzyme to denature? |
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Definition
| Too high temperature or pH. |
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Term
| What happens to a denatured enzyme? |
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Definition
| It's active site changes so it cannot react. |
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Term
| Describe active transport. |
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Definition
| Process in which dissolved molecules move across a cell membrane from a low concentration to a high concentration. Molecules move against the concentration gradient - therefore needing energy from the cell. |
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Term
| Give an example and describe the process of active transport in a human being. |
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Definition
| During the digestion of food in the small intestine. Carbohydrates are broken down into sugars such as glucose, and the glucose is absorbed by active transport into the villi, to be passed into the bloodstream and taken round the body. |
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Term
| What protein absorbs a needed molecule to pass through a cell membrane in active transport? |
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Definition
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Term
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Definition
| Photosynthesis is a process used by plants in which energy from sunlight is used to convert carbon dioxide and water into molecules needed for growth. |
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Term
| What part of the plant and chemical absorbs light energy? |
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Definition
| Chloroplasts & chlorphyll. |
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Term
| What is the word equation for photosynthesis? |
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Definition
| Carbon dioxide + water --light energy--> glucose + oxygen |
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Term
| What is the chemical equation for photosynthesis? |
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Definition
| 6CO2 + 6H2O --light energy--> C6H12O6 + 6O2 |
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Term
| Give 3 ways how glucose is used in cells. |
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Definition
-Converted into starch for storage. Can be converted back into glucose when the plant requires it.
-Converted into chemicals required for the growth of plant cells, such as cellulose.
-Broken down during the process of respiration, releasing energy in glucose molecules. |
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Term
[image]
Explain what each part of a plant cell does. |
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Definition
Cell wall - strengthens the cell
Vacuole - containing cell sap to keep the cell turgid
Chloroplasts - contain chlorophyll and enzymes needed for reactions inphotosynthesis
Cell membrane - controls the passage of molecules going in and out the cell.
Cytoplasm- enzymes and other proteins made for photosynthesis are made in here.
Nucleus - controls the cell and contains DNA for the proteins that need to be made during photosynthesis. |
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Term
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Definition
| The movement of particles from a high concentration to a low concentration - requires no energy. |
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Term
| When can particles diffuse? |
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Definition
| When they are free to move. |
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Term
| Give an example of diffusion in plants. |
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Definition
High concentration of carbon dioxide diffuses into a leaf that has a low concentration.
High concentration of oxygen inside a leaf diffuses into the air. |
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Term
| What do you need for osmosis to occur? |
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Definition
-2 different concentrations of solutions.
-A partially permable membrane to seperate them. |
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Term
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Definition
| The movement of water from a less concentrated solution to a more concentrated solution through a partially permable membrane. |
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Term
| Where does osmosis occur in plants? |
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Definition
| In the roots and plant cells. |
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Term
| Give 3 examples on how root hair cells have adapted to absorbing water by osmosis? |
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Definition
-Large surface area.
-Thin walls.
-Close to the xylem cells so water is easily transported up the plant. |
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Term
| How do root hair cells absorb minerals from the soil? |
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Definition
| The hair root cells have carrier molecules on the surface to pick up the minerals using active transport. |
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Term
| Name and explain the 3 factors that affect the rate of photosynthesis? |
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Definition
-Light. Without enough light, a plant cannot photosynthesise quickly.
-Carbon dioxide concentration. A plant cannot photosynthesise with insuffiecent carbon dioxide.
-Temperature. If a plant is too hot or too cold, it cannot photosynthesise. |
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Term
| What can farmers do to make sure their plants are always photosynthesising? |
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Definition
| They can store the plants in greenhouses and provide artificial lighting so the plants can continue to photosynthesise in night time hours. They can also use parffin lights because these produce carbon dioxide and heat. |
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Term
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Definition
| A quadrat is used because some people may want to find out how plants and animals differ from place to place. |
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Term
| What are the two processes of respiration? |
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Definition
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Term
| What does aerobic respiration need to work and where does it take place? |
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Definition
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Term
| What is the symbol equation for aerobic respiration? |
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Definition
| C6H12O6 + 6O2 --> 6CO2 + 6H2O (+ energy) |
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Term
| How is the energy released from respiration used? |
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Definition
-To make large molecules from smaller molecules.
-To allow muscles to contract in animals.
-To maintain a constant body temperature in birds and mammals. |
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Term
| When is anaerobic respiration used? Give examples when it is used. |
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Definition
When there is not enough oxygen for aerobic respiration.
-Used in plant roots in water logged soils.
-Bacteria in puncture wounds.
-Animals running away from prey. |
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Term
| What is the word equation for anaerobic respiration? |
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Definition
| glucose --> lactic acid (+ energy released.) |
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Term
| What is the word equation for anaerobic respiration in some plant cells and some micro-organisms? |
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Definition
| glucose --> ethanol + carbon dioxide (+ energy released) |
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Term
| Which type of respiration needs more energy per glucose molecule? |
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Definition
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Term
| What foods can be made from anaerobic respiration of yeast and bacteria? |
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Definition
| Bread, yoghurt and vinegar. |
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Term
| Describe the structure of a bacterial cell and name the functions of each part. |
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Definition
Cytoplasm - where enzymes are made and where reactions involved with respiration occur.
Cell membrane - controls what goes in and out of the cell such as gases and water.
Cell wall - Provide rigidity to maintain the cell shape.
Molecule of circular DNA - contains genetic code for enzymes involved in respiration. |
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Term
| Describe the structure of a yeast cell and function of each part. |
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Definition
Nucleus - contains genetic code for enzymes involved in respiration.
Cell membrane - Allows gases and water to pass in and out of the cell.
Cell wall - provides rigidity to maintain cell shape.
Cytoplasm - Enzymes are made and reactions involving respirations occur here.
Mitochondria - Contains enzymes for the reactions in aerobic respiration. |
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Term
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Definition
| When sugars are converted into ethanol during anaerobic respiration. |
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