1 / 72

Cells

Cells. Bacterial cell – genetic information not contained within a nucleus. Diffusion is the net movement of particles from a high concentration to a low concentration down the concentration gradient until an equilibrium is reached. Cell . Tissue. Organ. Organ system.

abiba
Download Presentation

Cells

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cells

  2. Bacterial cell – genetic information not contained within a nucleus

  3. Diffusion is the net movement of particles from a high concentration to a low concentration down the concentration gradient until an equilibrium is reached

  4. Cell Tissue Organ Organ system

  5. Organs are made of tissues. The stomach is an organ that contains: ■ muscular tissue, to churn the contents ■ glandular tissue, to produce digestive juices ■ epithelial tissue, to cover the outside and the inside of the stomach.

  6. Plants

  7. Examples of plant tissues include: • epidermal tissues, which cover the plant • mesophyll, which carries out photosynthesis • xylem and phloem, which transport substances around the plant

  8. FOOD (GLUCOSE) + CARBON DIOXIDE + WATER OXYGEN Taken in through holes in the leaves as a gas in air Taken in through the roots from soil Made by photosynthesis and stored as starch in leaves, roots, stems, etc. waste product exhaled With light and chlorophyll We know that plants make their own food from sunlight. They are the producers in the food chain. This is done in the green parts of the plant, e.g. upper surface of the leaves.

  9. LIMITING FACTORS? • LIGHT INTENSITY • TEMPERATURE • CARBON DIOXIDE

  10. Paraffin lamps have traditionally been used in greenhouses. Their use increases the rate of photosynthesis because as well as the light generated from the lamps, the burning paraffin produces heat and carbon dioxide too The use of artificial light allows photosynthesis to continue beyond daylight hours. Bright lights also provide a higher-than-normal light intensity. The use of artificial heating allows photosynthesis to continue at an increased rate.

  11. Converted into insoluble starch for storage Used in respiration Glucose To produce fats and oils for storage To produce cellulose for cell walls To produce proteins To produce proteins, plants also use nitrate ions that are absorbed from the soil.

  12. DISTRIBUTION OF ORGANISMS

  13. enzymes

  14. Proteins act as: • structural components of tissues such as muscles • hormones • antibodies • catalysts • Catalysts increase the rate of chemical reactions. Biological catalysts are called enzymes. Enzymes are proteins.

  15. Enzymes are protein molecules, and so are made up of long chains of amino acids. Most enzymes contain between 100 and 1,000 amino acids. These long chains are folded to produce a unique 3D shape which enables other molecules to fit into the protein.

  16. The shape of an enzyme is vital for the enzyme’s function. High temperatures change the shape. Different enzymes work best at different pH values.

  17. This is what happens at the active site + + enzyme enzyme ↔ enzyme-reactant complex ↔ + + reactant products ↔ ↔

  18. heat pH normal denatured If the temperature and pH changes sufficiently beyond an enzyme’s optimum, the shape of the enzyme irreversibly changes. This affects the shape of the active site and means that the enzyme will no longer work. When this happens the enzyme is denatured.

  19. Effect of pH… A change in the pH changes the shape of the protein molecule, the enzyme loses its active site and so can no longer act as a catalyst.

  20. Effect of temperature…

  21. QUIZ! • What are biological catalysts called? • What are enzymes made of? • What is the place on the enzyme where the reactant molecule binds called? • What does it mean when an enzyme is denatured? • What two factors can affect enzyme action?

  22. Some enzymes work outside the body cells. The digestive enzymes are produced by specialised cells in glands and in the lining of the gut. The enzymes then pass out of the cells into the gut where they come into contact with food molecules. They catalyse the breakdown of large INSOLUBLE molecules into smaller SOLUBLE molecules.

  23. The stomach produces hydrochloric acid to create the optimum conditions for the protease enzymes in the stomach

  24. Bile neutralises the acid that was added to food in the stomach. This provides alkaline conditions in which enzymes in the small intestine work most effectively.

  25. QUIZ! • Name the enzyme that breaks down fats? • Name the enzyme that breaks down proteins? • Name the enzyme that breaks down carbohydrates? • What are fats broken down into? • What are proteins broken down into? • What are carbohydrates broken down into? • Where is amylase made? • Where is protease made? • Where is lipase made? • Where is bile produced? • Where is it stored? • What does it do?

  26. ENZYMES IN INDUSTRY From microorganisms More effective at low temperatures than other washing powders Isomerase – converts glucose into fructose

  27. In industry, enzymes are used to bring about reactions at normal temperatures and pressures that would otherwise require expensive, energy-demanding equipment. • However, most enzymes are denatured at high temperatures and many are costly to produce.

  28. QUIZ! • What type of organisms produce enzymes that are used in industry? • What enzymes are found in washing powders? • What enzyme converts glucose into fructose? • Why is fructose used in slimming foods rather than glucose?

  29. respiration

  30. useful! waste product exhaled waste product exhaled from the digestive system from the breathing system AEROBIC Respirationis the process that the body uses to release energy from digested food (glucose): energy glucose water oxygen carbon dioxide Happens in all cells all the time in plants & animals inside mitochondria

  31. Which cells contain more mitochondria? Why? • Muscles, liver and kidneys • They require more energy • They use energy at a higher rate, especially during exercise The folded layers produce a large surface area for the chemical reactions The large surface area means more enzymes can attach to the substrates to catalyse the reactions

  32. REASONS • Respiration releases energy from the food we eat so body cells can use it • Builds large molecules up from smaller ones to make new cell material (synthesis reactions) – example – sugars and nitrates are built into amino acids which are then used to make proteins • Makes your muscles contract – whether aware of or not – e.g. sleeping – heart beats, breathe, gut churns! • On cold days we use energy to keep warm and on hot days use energy to sweat and keep cool – WARM BLOODED

  33. QUIZ! • Write the equation for aerobic respiration • Where does respiration occur? • Which cells contain more mitochondria? • Give two reasons for respiration

  34. What changes happen during exercise?

  35. What do these changes mean? • Increase the blood flow to the muscles and so increase the supply of glucose and oxygen and increase the rate of removal of carbon dioxide.

More Related