Topic 1.2 Ultrastructure of Cells

Question 1

Electron Microscope

Answer 1

electrons have a shorter wavelength than light waves
pros: high resolution; can see ultrastructure of the cell
cons: cannot view live specimens so you cannot see the processes occurring inside
SEM: display enhanced depth to map surface of objects (3D)
TEM: high-resolution of cross section of objects

Question 2

Light Microscope

Answer 2

• lower resolution
• up to 1000x magnification
  pros: can view live specimen and witness cell division + other processes
  cons: lower resolution
• uses beam of light instead of beams of electrons

Question 3

Benefits of compartmentalization

Answer 3

1. efficiency of metabolism- enzymes and substrates are localized and concentrated
2. localized conditions - pH and other factors can be kept at optimal levels in one part of the cell
3. toxic/damaging substances (e.g. digestive enzymes that could digest the cell itself) are stored in lysosomes
4. numbers and locations of organelles can be changed dependent on the cell’s requirements

Question 3

Benefits of compartmentalization

Answer 3

1. efficiency of metabolism- enzymes and substrates are localized and concentrated
2. localized conditions - pH and other factors can be kept at optimal levels in one part of the cell
3. toxic/damaging substances isolated - digestive enzymes (that could digest the cell itself) are kept within the lysosomes
4. numbers and locations of organelles can be changed depending on cell’s needs

Question 4

size of ribosomes in mitochondria, prokaryotes, and chloroplasts

Answer 4

70s

Question 5

what size of ribosome is found on the RER and in the cytoplasm

Answer 5

80s

Question 6

Explain Binary Fission

Answer 6

DNA is replicated semiconservatively and the two loops attach to the membrane which elongates and pinches off (cytokinesis) forming two daughter cells, the daughter cells are genetically identical