Biology: Cells and Cell Transport

Cells

• Basic structural and functional units of life
• Consist of:
  • Cell membrane (plasma membrane): semi-permeable membrane that separates cell from environment
  • Cytoplasm: jelly-like substance inside cell membrane
  • Nucleus: contains genetic material (DNA)
• Cell types:
  • Prokaryotic cells: no nucleus, e.g. bacteria
  • Eukaryotic cells: have nucleus, e.g. plants, animals, fungi

Cell Transport

• Movement of molecules across cell membrane
• Types of transport:
  • Passive transport:
    • Diffusion: movement of molecules from high to low concentration
    • Osmosis: movement of water molecules from high to low concentration
  • Active transport: movement of molecules from low to high concentration using energy

Photosynthesis

• Process by which plants, algae, and some bacteria produce glucose from sunlight, water, and carbon dioxide
• Equation: 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2
• Importance: produces oxygen and glucose for energy

Cellular Respiration

• Process by which cells generate energy from glucose
• Equation: C6H12O6 (glucose) + 6O2 → 6CO2 + 6H2O + ATP (energy)
• Types of respiration:
  • Aerobic respiration: uses oxygen, produces ATP
  • Anaerobic respiration: does not use oxygen, produces less ATP

Ecosystems

• Communities of living and non-living things interacting with each other
• Components:
  • Biotic factors: living things (plants, animals, microorganisms)
  • Abiotic factors: non-living things (water, sunlight, temperature, soil)
• Interactions:
  • Producers: convert sunlight into energy (plants, algae)
  • Consumers: obtain energy by consuming other organisms
  • Decomposers: break down dead organisms into nutrients

Genetics

• Study of heredity and variation
• Key concepts:
  • DNA: genetic material that contains instructions for growth and development
  • Genes: segments of DNA that code for specific traits
  • Traits: characteristics of an organism (e.g. eye color, height)
  • Inheritance: passing of traits from parents to offspring

Cells

• Basic units of life, consisting of cell membrane, cytoplasm, and nucleus
• Cell membrane is semi-permeable, separating cell from environment
• Cytoplasm is a jelly-like substance inside cell membrane
• Nucleus contains genetic material (DNA)

Cell Types

• Prokaryotic cells: lack nucleus, e.g. bacteria
• Eukaryotic cells: have nucleus, e.g. plants, animals, fungi

Cell Transport

• Movement of molecules across cell membrane
• Passive transport: diffusion and osmosis
• Diffusion: movement of molecules from high to low concentration
• Osmosis: movement of water molecules from high to low concentration
• Active transport: movement of molecules from low to high concentration using energy

Photosynthesis

• Process by which plants, algae, and some bacteria produce glucose from sunlight, water, and carbon dioxide
• Equation: 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2
• Produces oxygen and glucose for energy

Cellular Respiration

• Process by which cells generate energy from glucose
• Equation: C6H12O6 (glucose) + 6O2 → 6CO2 + 6H2O + ATP (energy)
• Aerobic respiration: uses oxygen, produces ATP
• Anaerobic respiration: does not use oxygen, produces less ATP

Ecosystems

• Communities of living and non-living things interacting with each other
• Biotic factors: living things (plants, animals, microorganisms)
• Abiotic factors: non-living things (water, sunlight, temperature, soil)
• Producers: convert sunlight into energy (plants, algae)
• Consumers: obtain energy by consuming other organisms
• Decomposers: break down dead organisms into nutrients

Genetics

• Study of heredity and variation
• DNA: genetic material that contains instructions for growth and development
• Genes: segments of DNA that code for specific traits
• Traits: characteristics of an organism (e.g. eye color, height)
• Inheritance: passing of traits from parents to offspring