Cell Biology

Question 1

What is epithelium?

Answer 1

A layer of cells

Question 2

What is a colon?

Answer 2

Large intestine

Question 3

What is a cell?

Answer 3

Most basic structural unit of all living organisms

Question 4

Which technique is used to visualise the organelles within a cell?

Answer 4

Electron microscopy

Question 5

What’s the difference between transmission EM and scanning EM?

Answer 5

Transmission EM - requires very thin specimens and heavy metal compound stainsScanning EM - Visualisation from electrons scattering off metal-coated surface.

Question 6

What advantage does light microscopy have over electron microscopy?

Answer 6

Light microscopy can be used with sensitive highly specific stains on individual cells

Question 7

How are cells visible in light microscopy?

Answer 7

They are transparent, need stains or optical tricks

Question 8

What is the difference between bright field LM and fluorescence LM?

Answer 8

Bright field LM needs dense stains which are incompatible with living cells and have low specificity.Fluorescence LM allows greater sensitivity and more precise localisation

Question 9

What does immunofluorescence mean?

Answer 9

The use of sensitive highly specific stains to determine the location of an antibody or antigen (labelling with a fluorescent dye)

Question 10

What is chromatin?

Answer 10

DNA packed round histone proteins. Can be transcribed into RNA.

Question 11

What is the nucleolus?

Answer 11

A densely staining region where ribosomes are assembled

Question 12

What is the nuclear envelope?

Answer 12

A double membrane structure with pores for transport

Question 13

What happens in the nucleolus?

Answer 13

Ribosomes are assembled

Question 14

What is the importance of the nucleus?

Answer 14

Site of genetic material, transcription and where it’s controlled

Question 15

What is the endoplasmic reticulum?

Answer 15

Network occupying much but not all of the cytoplasm, double membrane structure

Question 16

What is the purpose of the Golgi apparatus?

Answer 16

Receives proteins and lipids (fats) from the rough endoplasmic reticulum, modifies some of them and sorts, concentrates and packs them into called vesicles. Depending on the contents these are despatched to one of three destinations:1: within the cell, to organelles called lysosomes.2: the plasma membrane of the cell3: outside of the cell.

Question 17

Name two significant stages of exocytosis

Answer 17

DockingFusion

Question 18

Where do you find the Golgi apparatus?

Answer 18

Single location, near the endoplasmic reticulum

Question 19

What is the purpose of a secretory vesicle?

Answer 19

Transporting material FROM Golgi TO cell surface

Question 20

What is an endosome?

Answer 20

Vesicle that formed from material entering cell via endocytosis

Question 21

Where are coated vesicles found?

Answer 21

Throughout cell; near cell surface in relation to endocytosis

Question 22

Where would material, that has travelled into the cell by endocytosis, be processed initially?

Answer 22

Endosomes

Question 23

Where are endosomes found in eukaryotic cells?

Answer 23

Throughout cell including periphery

Question 24

What is the cell periphery?

Answer 24

The part of a cell encompassing the cell cortex, the plasma membrane, and any external encapsulating structures (the outermost boundary of the cell with outer parts included)

Question 25

What are lysosomes?

Answer 25

The main waste disposal location; major site of degradation. A.K.A The suicide sac of the cell

Question 26

What is the difference between lysosomes and endosomes in terms of location?

Answer 26

Lysosomes would be more central in the cell than endosomes which are thoughout the cell, including the cell periphery

Question 27

Where are secretory vesicles found?

Answer 27

Throughout the cell

Question 28

What is the purpose of secretory vesicles?

Answer 28

To transport material from the Golgi apparatus to the cell surface

Question 29

What is the purpose of the sER?

Answer 29

A 'factory' that manufactures many of the products that a cell needs to function; associated with the production and metabolism of fats and steroid hormones

Question 30

What is the process of glycosylation?

Answer 30

Adding a polysaccharide chain to something (e.g. proteins and lipids)

Question 31

What are organelles of the exocytic pathway?

Answer 31

rER (protein synthesis) ---> Golgi apparatus (Modification, packaging etc.) --->Small transport vesicles ---> Various possible destinations  from 'trans' face of Golgi

Question 32

After proteins have been made, modified and packaged where could they go?

Answer 32

Plasma membrane/Secretory granules

Question 33

What is regulated secretion?

Answer 33

Vesicles from the Golgi fuse and dock at the cell membrane to form secretory vesicles.  A signal is received within the cell causing the secretory vesicles to complete the secretion process via exocytosis

Question 34

What is the alternative to regulated secretion?

Answer 34

Constitutive secretion

Question 35

What is constitutive secretion?

Answer 35

First the protein must move through the Golgi apparatus.  The protein reaches the cell membrane and completes the secretion process via exocytosis.

Question 36

What form of secretion do eukaryotic cells use and why?

Answer 36

All eukaryotic cells use constitutive secretion to maintain their plasma membranes.

Question 37

What is the default form of secretion?

Answer 37

Regulatory

Question 38

Secretory granules store substances for which type of secretion?

Answer 38

Regulatory

Question 39

What level do viruses infect organisms at?

Answer 39

Unicellular level

Question 40

How does viral replication take place?

Answer 40

Invasion 'hiijacks' part of the endocytic pathway Replication hiijacks normal nucleic acid and protein synthesis pathways Assembly and budding of new viruses exploits the exocytic pathway

Question 41

Why are viruses technically not living organisms?

Answer 41

They cannot replicate without exploiting the reproductive mechanisms of a host

Question 42

Why is it hard to develop antiviral drugs?

Answer 42

Viruses use normal cellular processes so stopping them would kill lots of body cells (not specific enough)

Question 43

Where are mitochondria found?

Answer 43

Throughout the cell (NOT including periphery)

Question 44

What are perixosomes?

Answer 44

The site of oxidative reactions with H2O2(H2O2 can then be converted to H2O and O2 by catalase)

Question 45

Where are perixosomes found?

Answer 45

Throughout the cell

Question 46

True or false? Mitochondria are more abundant than perixosomes?

Answer 46

True

Question 47

True or false? Mitochondria contains it's own DNA

Answer 47

True (Circular)

Question 48

What is the site of fatty acid metabolism?

Answer 48

Peroxisomes

Question 49

What are immediate filaments?

Answer 49

Structural components of the cell

Question 50

Where are immediate filaments found in the cell?

Answer 50

Throughout

Question 51

Where is actin, an immediate filament, most concentrated in the cell?

Answer 51

Near the cell surface

Question 52

Where are microtubules found in a eukaryotic cell?

Answer 52

Throughout; extending radially from the centre

Question 53

What is the purpose of centrosomes?

Answer 53

the major microtubule-organising centre of the cell 

Question 54

Where are centrosomes found?

Answer 54

In the cytoplasm outside the nucleus but often near to it.

Question 55

What are centrioles?

Answer 55

Cylindrical structures that are composed of groupings of microtubules. They aid in mitosis, possibly involved in spindle assembly during mitosis.

Question 56

What is the cytoskeleton?

Answer 56

Filamentous structures throughout the cytoplasm

Question 57

What are the 3 cytoskeletal systems?

Answer 57

Actin filaments Intermediate filaments | Microtubules

Question 58

What is the purpose of the cytoskeleton?

Answer 58

Generate cell shape Movement Internal organisation