Cell biology

• What can a light microscope see?

  Basic cell structures
• What is used to see cell structures?

  Electron microscope
• What are cell structures called?

  Organelles
• What are the functions of the nucleus, ribosomes, cytoplasm, cell wall, vacuole, chloroplasts, mitochondria, and cell membrane?

  • Nucleus: Controls cell activity & contains genetic information
  • Ribosomes: Synthesise proteins for repair and interaction
  • Cytoplasm: Site of chemical reactions
  • Cell wall: Provides support and maintains shape of plant cells
  • Vacuole: Maintains plant structure
  • Chloroplasts: Site of photosynthesis
  • Mitochondria: Site of aerobic respiration
  • Cell membrane: contains proteins, allows molecules to enter and leave the cell
• What is the function of the nucleus?

  Controls cell activity & contains genetic information
• What do ribosomes synthesise?

  Proteins
• What is the role of the cytoplasm?

  Site of chemical reactions
• What does the cell wall provide for plant cells?

  Support and maintains shape
• What does the vacuole store?

  Water, salts, nutrients
• What is the site of photosynthesis?

  Chloroplasts
• What is the site of aerobic respiration?

  Mitochondria
• Where are proteins made in the cell?

  ribosomes
• What components do plant and animal cells share?

  • Cell membrane
  • Cytoplasm
  • Nucleus
• What unique components do plant cells have compared to animal cells?

  • Vacuole
  • Chloroplast
  • Cell wall
• What type of cell is characterized by a cell wall and chloroplasts?

  Plant cell
• What type of cell lacks a cell wall?

  Animal cell
• What does a cell membrane allow substances to do?

  Pass in and out of the cell
• What is the composition of the cell membrane?

  Double layer of phospholipids and protein
• How do proteins in the cell membrane function?

  They allow substances to pass through
• Which small molecules can pass through the membrane?

  Oxygen, water, carbon dioxide, amino acids, glucose
• Which large molecules cannot pass through the membrane?

  Starch and protein
• What does the plasma membrane contain?

  Proteins and phospholipids molecules
• What is the characteristic of the plasma membrane?

  It is selectively permeable
• What are the three methods of transport across the membrane?

  • Diffusion
  • Osmosis
  • Active transport
• What is a concentration gradient?

  Difference in concentration between two regions
• What is the process by which oxygen diffuses from the lungs?

  Oxygen diffuses into red blood cells
• What happens to carbon dioxide in the blood? Lung diffusion

  It diffuses out into the lungs
• Why is diffusion important for plants during photosynthesis? Plant Diffusion

  Carbon dioxide diffuses in, oxygen diffuses out
• What occurs in plants during the dark regarding gas exchange? Plant diffusion

  Oxygen diffuses in, carbon dioxide diffuses out
• What substances diffuse from the gut to the blood? Intestines

  Glucose and amino acids
• What is osmosis?

  Movement of water from high to low concentration
• Does osmosis require energy?

  No energy required
• What is a hypotonic solution?

  0.0% salt solution
• What is an isotonic solution?

  0.85% salt solution
• What is a hypertonic solution?

  2.0% salt solution
• What happens to red blood cells in a hypertonic solution?

  They lose water and shrink
• What occurs to plant cells in a hypotonic solution?

  They gain water and become turgid
• What is the effect of a hypertonic solution on plant cells?

  They undergo plasmolysis and shrink
• What is the structure of DNA?

  Double stranded helix shape
• What are the four bases of DNA?

  Guanine, cytosine, adenine, thymine