Exam Q's review Flashcards
explain the role of the membrane in the rough endoplasmic reticulum
1) compartmentalisation / maintain different
conditions from cell cytoplasm
2) separating proteins (synthesised) from cell
cytoplasm
3) hold, ribosomes / enzymes, in place
How does yeast do cell division?
budding
explain why early eukaryotes were able to grow more quickly than cells that did not possess mitochondria?
1) would be able to respire aerobically ✓
2) (this) produces more ATP ✓
3) ATP needed for , active transport / cell division
/ protein synthesis / DNA replication ✓
4) more ATP allows faster metabolic , processes
/ reactions ✓
tubulin is a globular protein tat can polymerise to form the cell cytoskeleton
one example of this is the formation of microtubules which form spindle fibre to move chromatids during mitosis and meiosis
describe three other cellular functions of the cytoskeleton?
mechanical strength (to cells) ✓
cell, support / stability /
maintains shape ✓
movement of (named), molecules / vesicles /
organelles within cell
holding organelles in position ✓
formation / movement, of, cilia / flagella ✓
cell movement / endocytosis / exocytosis /
phagocytosis / cytokinesis / described ✓
suggest two ways tubulin is essential to protein synthesis and secretion in eukaryotic cells
movement of mRNA from nucleus to ribosome✓
movement of polypeptides through the rER ✓
movement of vesicles from rER to Golgi ✓
movement of secretory vesicles from Golgi to
cell surface membrane✓
peroxisomes are vesicles usually containing enzymes such as catalase.
explain how peroxisomes an be moved around inside the cell?
attach to cytoskeleton (1)
moved by, protein motors / dynein (1)
explain how to measure the diameter of the nucleus of one of the white blood cells when observing the cells through a light microscope?
use eyepiece graticule ✓
calibrate graticule, using stage micrometer✓
measure the diameter of the nucleus in, epu / graticule
units ✓
take repeat measurements and calculate a mean
diameter (in epu) ✓
use calibrated epu to calculate diameter (of nucleus) (in
μm) / described ✓
discus the benefits of using stains when making slides for light microscopy
increases contrast
makes organelles, cells and components more visible/ clearer
as the bind to the stain
which stain should be chosen to bind to the phosphate group of DNA to make chromosomes more visible in light microscopy
methylene blue- a positively charged dye
(phosphate group of DNA is negatively charged)
compare TEM and SEM
TEM
-higher resolution
-2D image
- shows cell interior
SEM
-3D
-lower resolution
-shows cell surface
