Module 2.1 Cell Structure

Question 1

what is the function of cell surface membrane ?

Answer 1

controls what enters and leaves the cell
. site of cell communication via receptors
.

Question 2

What is the role of smooth endoplasmic reticulum

Answer 2

Transport of fats and lipids e.g steroid hormones

Question 3

What’s the role of lysosomes

Answer 3

Contains hydrolytic enzymes
Break down organelles / cells,food and pathogens

Question 4

What’s the role of ribosomes

Answer 4

Protein synthesis

Question 5

Name two features of plant cells that are not features of animals cells

Answer 5

Cellulose cell wall
Chloroplast
Plasmodesmata
largepermanent vacoule

Question 6

outline functions of vesicles ?

Answer 6

storage and transport of material around the and out of the cells
1. transport vesicles - contains molecules for trnasport around the cell
2. secretory vesicles containing molecules to the cell surface membrane to to be releases from the cell

Question 7

Describe the advantages of staining

Answer 7

Staining increases contrast
Makes visible to see more detail
Identify cell type or organelles

Question 8

what’s the role of Golgi apparatus ?

Answer 8

modifies proteins package and transport molecules around the cell

Question 9

what is the difference between prokaryotic and eukaryotic cells?

Answer 9

eukaryotic
. membrane bound organelles
. 80s ribosomes
Linear DNA packaged into chromosomes
prokaryotic :
-no membrane bound organelles
-70s ribosomes
cell wall made of peptidoglycan .
- circular DNA Freely floating in cytoplasm
.

Question 10

what are 3 types of microscopes ?

Answer 10

1. light microsope
2. scanning elelctron
3. transmission

Question 11

what is the magnifaction /resolution of light microscope ?

Answer 11

x1,500
200nm
produces 2D

Question 12

what is the magnifaction/resolution for scanning electron microscope ?

Answer 12

x200,000
20nm
Produces 3D IMAGE

Question 13

what is the magnification and resolution of transmission electron microscope ?

Answer 13

x 2,000,000
0.1nm
Produces 2D image

Question 14

define resolution ?

Answer 14

the ability to distinguish between two separate entities in great detail .

Question 15

what is the equation for magnifaction

Answer 15

magnification =size of image /actual object

Question 16

outline importance of the cytoskeleton ?

Answer 16

MicrofilAments -contractile fibre made of actin protein
cell movement and contraction of the cell
Microtubules - globular tubular whcih forms scaffolding determines the shape of the cell
- forms a spindle fibres separate chromosomes
- intermediate filaments - mechanical strenghts
-

Question 16

state functions of the lysosomes ?

Answer 16

degrade waste materials including worn out organelles and pathogens

Question 17

what are the organelles involved in protein synthesis ?

Answer 17

Ribosomes
RER
Golgi Apparatus
The cytoskeleton
Vesicles

Question 18

outline the process of protein synthesis

Answer 18

A Copy of genetic material -mRNA is produced in the nucleus and leaves through nuclear pores
-mRNA moves through the cytoplasm and attaches to the ribosomes and the protein polypeptide chain is made
-the protein pass into the Cisternae of RER and folds within
the folded protein are packaged into transport vesicles
- the protein in the transport vesicles move toward the Golgi Apparatus
using cytoskeleton
- the vesicles fuse with the cis of the Golgi Apparatus
and proteins enter cisternae of the Golgi stacks and become modified
- protein leave Golgi Apparatus in secretory vesicles at the trans face of the Golgi
- vesicles move along the cytoskeleton to the cell surface membrane -fuse and proteins are released .
-some vesicles become hydrolytic enzyme stay in the cell to become lysosomes .

Question 19

compare the difference between eukaryotic and prokaryotic cells ?

Answer 19

eukaryotic
80s ribosomes
membrane bound organelle e.g nucleus
- linear DNA Associated with histone proteins
- complex
cell wall made of cellulose
can be multicellualr or unicellular

prokaryotic
70s ribosomes
-no membrane bound organelle
genetic material contained in nucleotid
reproduce by binary fission
-

Question 20

how does flagella in prokaryotic cells differ from eukaryotic cells ?

Answer 20

prokaryotic flagella is thinner
- doesn’t have the 9+2 arrangement
- the energy to rotate is not supplied by ATP
SUPPLIED BY PROCESS CALLED chemiosmosis.

Question 21

what is the function of chloroplast ?

Answer 21

site of protein synthesis
- enzymes are embedded in thylakoid membranes

Question 22

state the functions of vacoule ?

Answer 22

Tonoplast membrane - regulates the mov of molecules in and out of the vacoule
- store molecules within the cell
- works to maintain turgor pressure which keeps the plant cells swollen and rigid

Question 23

what is the process of separating organelles known as ?

Answer 23

fractionation

Question 24

what is the order of cell fractionation ?

Answer 24

from heaviest to lightest
- nuclei
- chloroplast
-mitochondria
-lysosomes
-endoplasmic reticulum
ribosomes