B1.1.1 Cell Structure

• What are the two types of cells?

  1. Prokaryotic
  2. Eukaryotic
• What are the differences between Eukaryotic and Prokaryotic cells?

  Prokaryotic are much smaller.

  Eukaryotic cells contain membrane-bound organelles and a nucleus containing genetic material, while prokaryotics do not.
• What is the prokaryotic cell wall made of?

  Peptidoglycan
• How is genetic information stored in a prokaryotic cell?


  Found free within the cytoplasm as:

  • chromosomal DNA
  • plasmid DNA
• What are plasmids?

  • Small, circular loops of DNA found free in the cytoplasm and seperate from the main DNA
  • Carry genes that provide genetic advantages
• What is order of magnitude?

  A power to the base 10 used to quantify and compare size
• List the components in both plant and animal cells

  • Nucleus
  • Cytoplasm
  • Cell Membrane
  • Mitochondira
  • Ribosomes
• List the additional cell components found in plant cells

  • chloroplasts
  • permant vacule
  • cell wall
• Other than storing genetic information, what is the function of the nucleus?

  controls cellular activities
• describe the structure of the cytoplasm


  structure:

  • fluid component of the cell
  • contains organells, enzymes and dissolved ions and nutrients
• what is the function of the cytoplasm

  • site of cellular reactions e.g. first stage of respiration
  • transport medium
• what is the function of the cell membrane?


  controls the entry and exit of materials into and out the cell
• what is the function of mitochondria?

  site of larger stages of aerobic respiration in which ATP is produced
• what is the function of ribosomes?

  joins amino acids in a specific order during translation for the synthesis of proteins
• what is the plant wall made of?

  cellulose
• what is the function of the plant cell wall?

  • provides strength
  • prevents the cell bursting when water enters by osmosis
• what does the permanent vacuole contain?

  cell sap
• what is the function of the permant vacuole?

  supports the cell
• what is the function of chloroplasts?

  site of photosynthesis
• describe how sperm cells in animals are adapted to their functions

  • haploid nucleus (contains genetic information)
  • tail (enables movement)
  • mitochondria (provide energy for tail movement)
  • acrosome (contains enzymes that digest the egg cell membrane)
• Describe how nerve cells in animals are adapted to their function

  • long axon (electrical impulses travel through the body)
  • dendrites (recieve impulses)
  • myelin sheath (insulates the axon and speeds up the transmission)
• describe how muscle cells are adapted to their function

  • arrangement of protein filaments
  • mitochondria
  • merged cells in skeletal msucle
• describe how root hair cells in plants are adapted to their function

  • large surface area
  • thin walls
• describe how xylem cells in plants are adapted to their function

  • no upper or lower margins between cells
  • thick, woody side walls
• Eukaryotic cells

  Plant and animal cells
• Differences between eukaryotic and prokaryotic cells

  • Prokaryotic cells are much smaller than eukaryotic cells
  • Eukaryotic cells contain membrane bound-organelles and a nucleus containing genetic material, while prokaryotes do not
• Prokaryotic cell wall

  Composed of peptidoglycan
• Genetic information storage in prokaryotic cells

  Found free within the cytoplasm as chromosomal DNA (single large loop of circular DNA) and plasmid DNA
• Plasmids

  Small, circular loops of DNA found free in the cytoplasm and separate from the main DNA, carrying genes that provide genetic advantages e.g. antibiotic resistance
• Order of magnitude

  A power to the base 10 used to quantify and compare size
• Centimetre (cm)

  1 x 10-2 metres
• Millimetre (mm)

  1 × 10-3 metres
• Micrometre (µm)

  1 × 10-6 metres
• Nanometre (nm)

  1 x 10-9 metres
• Difference in order of magnitude between a human hair (length = 100 µm) and the HIV virus (length = 100 nm)

  100 µm = 10-4 m, 100 nm = 10-7 m, -4-(-7) = -4 + 7 = 3
• Components of both plant and animal cells

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• Additional cell components found in plant cells

  • Chloroplasts
  • Permanent vacuole
  • Cell wall
• Function of the nucleus (other than storing genetic information)

  Controls cellular activities
• Structure of the cytoplasm

  Fluid component of the cell, containing organelles, enzymes and dissolved ions and nutrients
• Function of the cytoplasm

  Site of cellular reactions e.g. first stage of respiration, transport medium