cell structure ✩

• Cells

  The basic building blocks of life that can replicate independently
• Multicellular organisms like animals and plants contain many cells that divide to grow or replace dead cells, not to create new organisms
• Bacteria are single-celled prokaryotic organisms
• Subcellular structures common to animal and plant cells

  • Cell membrane
  • Nucleus
  • Cytoplasm
  • Mitochondria
  • Ribosomes
• Plant cells

  • Have a rigid cell wall made of cellulose
  • Contain a permanent vacuole with cell sap
  • Contain chloroplasts for photosynthesis
• Bacterial cells

  • Lack mitochondria and chloroplasts
  • Have a single circular strand of DNA instead of a nucleus
  • May have additional plasmids
  • May have flagella for movement
• Photosynthesis occurs in the chloroplasts of plant cells, using chlorophyll to absorb light energy
• Aerobic respiration in mitochondria releases energy for the cell
• Characteristics of living things (organisms)

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• Acronym for the 7 key features

  MRS GRAN
• Non-living things may have some of these features, but only living things have all 7
• Movement

  Ability of organisms to move, either the whole organism or just part of it
• Respiration

  Chemical reactions that break down nutrient molecules to release energy for metabolism
• Sensitivity

  Ability to detect and respond to changes in the internal or external environment
• Growth

  Permanent increase in size and dry mass
• Reproduction

  Process that makes more of the same kind of organism
• Excretion

  Removal of waste products of metabolism and substances in excess of requirements
• Nutrition

  Taking in of materials for energy, growth and development
• All living organisms are made up of one or more cells
• Viruses are not considered living organisms because they don't meet all 7 requirements
• Nanometers

  Smallest unit of length you need to know
• Units of length

  • Nanometers
  • Micrometers
  • Millimeters
  • Meters
  • Kilometers
• Each unit is 1000 times bigger or smaller than the one next to it
• Converting between units of length

  1. Divide by 1,000 to convert to a larger unit

  2. Multiply by 1,000 to convert to a smaller unit
• To convert between non-adjacent units, convert in steps
• • Naked eye can see down to 100 micrometers
  • Light microscope can see down to 500 nanometers
  • Electron microscope can see down to 0.1 nanometers
• Centimeters

  10 millimeters, 100 centimeters in a meter
• Converting centimeters

  1. To meters: divide by 100

  2. To millimeters: multiply by 10
• Mitochondria are responsible for producing energy through aerobic respiration.
• animal cell

  1. cell membrane
  2. nucleus
  3. mitochondria
  4. ribosomes
  5. cytoplasm
• plant cell

  1. cell membrane
  2. nucleus
  3. mitochondria
  4. ribosomes
  5. cytoplasm
  6. permanent vacuole
  7. chloroplasts
  8. cell wall
• difference between animal cell and plant cell

  plant cells contain a permanent vacuole, chloroplasts and a cell wall, unlike animal cells
• cell membrane

  controls the movement of substances in and out of a cell
• nucleus

  contains DNA/ genetic material and controls all activities of the cell
• mitochondria

  where energy is released through respiration
• ribosomes

  the site of protein synthesis
• cytoplasm

  jelly-like substance, where chemical reactions happen
• permanent vacuole

  contains cell sap
• chloroplasts

  contain chlorophyll to absorb light energy for photosynthesis
• cell wall

  made of cellulose, which strengthens the cell