Basic Cell Structure

Question 1

What are the functions of the plasmalemma (plasma membrane)?

Answer 1

Selective permeability, transport of material along cell surface, endocytosis, exocytosis, intercellular adhesion, intercellular recognition, signal transduction

Question 2

Name the direction of movement through the golgi

Answer 2

Cis –> trans

Question 3

What shape is smooth ER on a scan?

Answer 3

Blebbed

Question 4

What is a peroxisome?

Answer 4

Contain enzymes degrade long chain fatty acids. In liver/kidney detoxify alcohol, phenols, formaldehyde

Question 5

What is the nuclear envelope?

Answer 5

phospholipid bilayer membrane which surrounds the genetic material and nucleolus

Question 6

In which cells are the mitochondrial cristae tubular?

Answer 6

steroidogenic cells

Question 7

What are the benefits of microvilli?

Answer 7

gives increased surface area but minimises an increase in volume

Question 8

Why is brown fat brown?

Answer 8

high levels of mitochondria

Question 9

Which structure of the cell is amphipathic?

Answer 9

the phospholipid bilayer (both hydrophilic and hydrophobic parts)

Question 10

What is the glycocalyx made of? And where is it positioned?

Answer 10

oligosaccharide and polysaccharide side chains outside the plasma membrane

Question 11

What is the role of intermediate filaments?

Answer 11

Form tough supporting meshwork in cytoplasm, also found beneath inner nuclear membrane forming nuclear lamina

Question 12

Name the function of the smooth ER

Answer 12

LIPID production, storage, transport

Question 13

Describe the structure of a mitochondria

Answer 13

2 membrane, inner membrane folds = cristae (site of oxidation of respiratory chain), matrix = space between folds

Question 14

Name the function of rough ER

Answer 14

Protein synthesis. inter = between cisternae. Intra = inside cisternae

Question 15

Where is smooth ER commonly found?

Answer 15

liver, mammary glands, ovaries, testis

Question 16

Role of the golgi?

Answer 16

vesicles with proteins from rER go to golgi to be modified, concentrated and then bud off to be exported outside the cell or form a lysosome

Question 17

What organelle is found is both prokaryotes and eukaryotes?

Answer 17

ribosomes

Question 18

What is a lysosome and its enzymes?

Answer 18

Contains glycosidases, proteases and sulfatases that break substances into smaller molecules

Question 19

What is special about mitochondrial DNA?

Answer 19

maternally inherited DNA, contain characteristically prokaryotic RNA

Question 20

What is the function of the mitochondria?

Answer 20

powerhouse, ATP by oxidative phosphorylation

Question 21

Where will actin filaments (microfilaments) be found?

Answer 21

Underlying plasma membrane, part of the muscle contractile unit

Question 22

List cellular structural support in order of size

Answer 22

Actin 5-9nm, intermediate filament 10nm, microtubules 25nm

Question 23

Describe microtubules and its function?

Answer 23

Hollow cylinders made of protein tubulin.

Rigidness so can support other structures in the cell, ability to generate movement: moving centrioles during mitosis, cilia and flagella

Question 24

What is the difference between cytoplasm and cytosol?

Answer 24

Cytoplasm = everything inside the plasma membrane bar the nucleus: cytosol and the organelles

Cytosol = fluid surrounding the nucleus and the organelles = water, salts, macromolecules - 70% cell volume

Question 25

What is the nucleolus?

Answer 25

Site of ribosome synthesis

Question 26

What is a secondary lysosome?

Answer 26

A lysosome that has already fused with a bacteria and contains its residue

Question 27

why is it good for eukaryotic cells to be compartmentalized?

Answer 27

so that reactions dont interfere with each other, many can occur

Question 28

what word defines lipid production?

Answer 28

steriodogenesis

Question 29

what is the difference between a lysosome and peroxisome on a TEM?

Answer 29

peroxisomes are darker

Question 30

what is the limit of resolution?

Answer 30

the minimum distance at which 2 objects can be distinguished