1. eukarotic cells tools and techniques

Question 1

cell theory

Answer 1

cells are fundamental units of life
all organisms are composed of cells
all cells come from pre-existing cells
all cells are surrounded by a plasma membrane

Question 2

typical size of ourcells

Answer 2

20um

Question 3

size of prokaryotic cell

Answer 3

1um

Question 4

thermos aquiaticus is an example of

Answer 4

an archaea prokaryote

Question 5

all eukaryotes have 3

Answer 5

a nucleus, cytoskeleton and complex internal membrane systems

Question 6

model cell system for prokaryote, lower eukaryote and high eukaryote

Answer 6

e. coli
yeast s.cerevisiae
human tissue culture cells HeLa

Question 7

model animals 3

Answer 7

zebrafish for vertebrate development
drosophila for genetics
nematode worm for genome sequencing

Question 8

function of peroxisomes

Answer 8

break down fatty acids, alcohols and toxins

Question 9

Zellweger syndrome

Answer 9

caused by defects in making new peroxisomes

is an imbalance in lipid mtablosim

Question 10

nucleolus

Answer 10

rRNA transcribed here and ribosomal units assembled here

Question 11

endoplasmic reticulum

Answer 11

entry point to secretory pathway

makes secretory proteins, membrane proteins and lipids

Question 12

smooth ER

Answer 12

is abundant in human cells involved in lipid metabolism and in the liver for detoxification of lipid soluble compounds

Question 13

sarcoplasmic reticulum

Answer 13

is a ER derived calcium store in muscle cells, it has an important role during muscle contracting

Question 14

golgi

Answer 14

receives proteins and lipids as cargo from the ER

modifies cargo eg glycosylates proteins and sorts cargo to correct tlocation

Question 15

endomembrane system

Answer 15

nuclear envelope, endoplasmic reticulum and Golgi evolved from the plasma membrane

Question 16

where oes protein synthesis occur

Answer 16

in the cytosol

Question 17

microscopy

Answer 17

study of tissues cells subcellular compartments in a buiological context

Question 18

centrifugation is the isolation of subcellular organelles

Answer 18

chromatography is the purification of proteins and protein complexes

Question 19

gel electrophoresis, mass spectrometry

Answer 19

is the analysis of macromolecules proteins and DNA

Question 20

light microzopy

Answer 20

descriptive differences

live, chemically fixed cells used (preserved and stabilised for microscopy)

Question 21

DAPI and Hoechst

Answer 21

pluroescent dyes/probes which preferentially bind to DNA

Question 22

transmission electron microscopy

Answer 22

thin specimen section stained with heavy metals for contrast
detailed subcellular structure

Question 23

scanning EM

Answer 23

good for 3D images

Question 24

homogeniation

Answer 24

controlled rupture of plasma membrane, releases intact organelles

Question 25

centrifugation

Answer 25

homogenate is centrifuged, results in supernatant fluid containinf smaller and less dense components
pellet containing larger more dense components

Question 26

differential centrifucation

Answer 26

repeated centrifugation at progressively high speeds , fractionates the contents
low speed= whole cells nuclei cytoskeletons
med speed - mitochondria lysosomes and peroxisomes
high speed- closed fragment of er, small vesicles
v high speed - ribosomes and viruses

Question 27

velocity sedimentation

Answer 27

use sucrose gradient to get highly purified organelles eg ER and mitochondria

Question 28

SDS page

Answer 28

proteins have negatively charged detergent SDS bind to it to unfold/ denture it
reducing agent agen t to proteins to cleave the disuplide bonds
proteins separated by size. smaller= faster

Question 29

SDS page stainss

Answer 29

conassie blue
silver staoon
radiolabel

Question 30

immunoblotting

Answer 30

identify a specific protein using an antibody that recognises it
Blot the SDS PAGE by transferring onto nylon sheet

Question 31

peptide mapping

Answer 31

used to identify unknown proteins ina gelslice without using antibodies. use mass spectrometry

Question 32

gel filtration column chromatography

Answer 32

separates proteins by size. larger proteins pass through column more quicly

Question 33

ion exchange chromatograpphy

Answer 33

separates prtoeins by charge