B4 - Process of Life questions

Use the lock and key method to explain how enzymes function. Describe how different factors can affect the rate of reaction. (use the words = Enzyme, Catalyst, Rate of Reaction, Protein, Factor, pH, Temperature, Denature)An enzyme is a protein which speeds up a chemical reaction. These reactions include photosynthesis, respiration and proteins. An Enzyme is seen as a biological catalyst. A catalyst increase the rate of a chemical reaction without itself being changed or effected. Substrate molecules are fitted specific in the active site of an enzyme molecule. This is the lock and key method. Enzymes are effected by the factors pH and temperature. As the temperature increases, the rate of reaction in enzymes increase until it reaches an optimum of 37 degrees. As the temperature continues to increase further than 37 degrees the enzyme starts to denature changing the shape of the enzyme.The active site of an enzyme can be affected by the pH. If the pH is different or changed, the enzyme will stop working. 

Outline the Main stages of photosynthesis and describe what plants do with the glucose made in the process (Use the words = Light energy, Chlorophyll, Carbon dioxide, Water, Glucose, Oxygen, Starch & Cellulose)Photosynthesis is a process in plants. Photosynthesis is Carbon dioxide + Water → glucose + oxygen.Photosynthesis needs light energy which is absorbed by the green chemical chlorophyll. This energy allows the production of glucose by the reaction between carbon dioxide and water. Energy from the sun is used to convert carbon dioxide and water into molecules for growth. These molecules include sugars, enzymes and chlorophyll. Glucose contains the atoms carbon, hydrogen and oxygen. Glucose can be converted into chemicals required for the growth of the plant such as cellulose. Also, can be converted into starch, a storage molecule. The starch can be converted back to glucose when the plant needs it. 

Making use of sketched graphs, explain how different factors can affect the rate of photosynthesis and potentially be "limiting factors" (use the words = Photosynthesis, Temperature, Carbon dioxide, Light intensity, Limiting, Rate) The three factors that can affect the rate of reaction of Photosynthesis are: temperature, Light intensity and the concentration of carbon dioxide. Without light, photosynthesis can not produce as quickly even if there is enough carbon dioxide and water. As you increase the light intensity the rate of photosynthesis increases.Photosynthesis can be limited by not enough carbon dioxide in the air. Even if there is enough light, photosynthesis cannot function probably without carbon dioxide. As the amount of concentration of carbon dioxide increases the rate of photosynthesis increases.If the temperature is too cold than the rate of photosynthesis will decrease. If the temperature is too hot, photosynthesis cannot occur. 

Using a diagram to help you, describe the structure of a typical plant cell and explain the functions of each of the main components of the cell. (use the words = Cell, Chloroplast, Nucleus, DNA, Mitochondria, Cell wall, Cell membrane, Cytoplasm In a plant cell, the cell contains a nucleus which contains the plants DNA carrying genetic code for enzymes and other proteins used in photosynthesisThe cell wall  is the strength of the plant as it strengthens the cell.The cell membrane allows substances to diffuse in and out of the plant, such as the substances used in photosynthesis.In the cytoplasm - enzymes and other proteins for photosynthesis are made here.The vacuole contains cell sap from keeping the cell becoming swollen. In the mitochondria most of the energy released by respiration is here.The ribosomes are where protein synthesis happens here.

Compare and contrast the similar processes of diffusion, osmosis and active transport. (Use the words = Movement, molecules, high concentration, low concentration, partially permeable membrane, energy)Diffusion is a passive process of which molecules move down the concentration gradient from a high concentration to a low concentration. Diffusion happens when particles spread and are free to move. Osmosis is the process of the movement of water molecules which move from a low concentration to a high concentration through a partially permeable membrane. Active transport is the process which dissolved molecules move across a cell membrane from a low concentration to a high concentration. In active transport particles move against a concentration gradient, which means that active transport needs an input of energy.  

Compare the basic process of anaerobic and aerobic respiration. Describe situations where anaerobic respiration takes place and how it can be useful to humans (Use the words = oxygen, ethanol, lactic acid, carbon dioxide, bacteria, exercise, fermentation)Aerobic respiration needs oxygen to work.  Most of the chemical reactions that are involved in the process happen in the cell cytoplasm - mitochondria. Aerobic respiration:glucose + oxygen → carbon dioxide + waterThe energy released by respiration is used to make large molecules from smaller ones. In plants, for example, sugars, nitrates and other nutrients are converted into amino acids. Amino acids can then join together to make proteins. The energy is also used: To allow muscles to contract in animals To maintain a constant body temperature in birds and mammals Anaerobic respiration is a of type respiration that does not use oxygen. It is used when there is not enough oxygen for aerobic respiration. glucose→ lactic acid (+ energy released)Anaerobic respiration also takes place in plants and some microbial cells in the presence of little or no oxygen. Examples of this include the roots of plants in waterlogged soils and bacteria in puncture wounds.Anaerobic respiration in plant cells and some microorganisms (such as yeast) produces ethanol and carbon dioxide, as opposed to lactic acid. It can be summarised by the following equation:glucose → ethanol + carbon dioxide (+ energy released)Aerobic respiration releases more energy per glucose molecule than anaerobic respiration.Anaerobic respiration of microorganisms such as yeast can lead to the production of useful commodities. During anaerobic respiration sugars are converted into ethanol. This is called fermentation.When fermentation is performed on a larger scale using yeast, water, sugar and some other nutrients bioethanol can be made that can be used as a fuel.

Enzymes

photosynthesis

plant cell

diffusion, osmosis & Active transport

aerobic & anaerobic respiration