Cell bio - T1

• cytoplasm function

  contains dissolved nutrients and salts

  where most chemical reactions occur

  
• ribosome function

  site of protein synthesis

  
• mitochondria function

  cellular respiration

  -> releases energy

  
• cell membrane function

  regulates substances that come in and out of cell

  
• nucleus function

  contains the chromosomes or genetic material

  
• cell wall function

  protection, structural support

  
  

  NOT ANIMAL

  
• chloroplast function

  site of photosynthesis

  
  

  NOT ANIMAL

  
• permanent vacuole function


  stores cell sap

  
  

  PLANT ONLY

  
• single circular chromosome


  DNA structure of PROKARYOTES

  
• flagella

  whiplike tails found in one-celled organisms to aid in movement

  
• plasmid

  A small, circular section of extra DNA that confers one or more traits to a bacterium and can be reproduced separately from the main bacterial genetic code.

  
• prokaryotes vs eukaryotes

  - Prokaryotes have no nucleus or membrane bound organelles

  
  

  - prokaryotes are smaller
• how do bacteria reproduce ( + equation)

  binary fission

  
  

  2^amount of divisions
• differentiation

  the process in which cells form different types of cells (specialise)
• specialisation


  adapting to perform a specific function by gaining new sub-cellular structures
• plant vs animal specialisation


  animals - early stage

  plants - maintain ability throughout life
• examples of specialised cells

  sperm cells

  nerve cells

  muscle cells

  root hair cells

  phloem

  xylem cells
• how are sperm cells adapted for function


  - flagellum; swim towards egg

  - lots of mitochondria; lots of energy

  - acrosome that relates enzymes to digest egg membrane
• how are nerve cells adapted for function

  - long axons

  - myelin sheath; insulates and speeds up impulses

  - extensions and branches
• how are muscle cells adapted for function

  mitochondria; muscle contraction
• how are root hair cells adapted for function

  large SA

  thin wall; osmosis
• how are xylem cells adapted for function

  -no end walls

  -lignin to withstand the high pressure

  -hollow tubes of dead cells
• how are phloem cells adapted for function

  -pores in end walls

  -companion cells provide energy for transport
• magnification equation

  magnification = image size / actual size
• electron vs light microscopes

  light uses ray of light; electron uses beam of electrons
• Pros and cons of light microscope

  Pros: cheap, portable, easy to use, can study living specimens.

  Cons: Limited magnification, poor resolution, only outlines of structures
• TEM vs SEM microscopes


  SEM - 3d images

  TEM - highest magnification
• chromosome


  A threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins.

  
  

  structure made of DNA that codes for all of an organisms characteristics
• gene

  section of DNA on a chromosome that contains instructions for making specific proteins (genetic info for one trait)
• chromosomes in human body cell

  46 (23 pairs - diploid)
• chromosomes in human gamete

  23 chromosomes (haploid)
• female chromosomes


  XX
• male chromosomes

  XY
• how do new diploid cells form

  mitosis
• why do cells divide by mitosis

  growth, repair and development
• what are the stages of cell growth and division called

  the cell cycle
• what are the stages of the cell cycle


  1) Interphase - DNA replicates, inc. in number of sub-cellular structures

  
  

  2) Mitosis - one set of chromosomes pulled to opposite ends of cell; nucleus divides

  
  

  3) Cytokinesis - cytoplasm and cell membranes divide

  
• what is produced from mitosis

  2 identical daughter cells
• equation for estimating length of stage of cell cycle from image

  observed number of cells at stage

  --------------------------------------- x total length of cell cycle

  total number of cells observed
• stem cell


  undifferntiated cell that can give rise to one or more types of specialized cells