Lecture 1: The Cell

Question 1

What is the structure and location of the RER?

Answer 1

Network of membranes studded with ribosomes - RNA. The RER is continous with the nuclear membrane

Question 2

What is the nucleus and when does it reform?

Answer 2

The command and control centre of the cell. Contains DNA in eukaryotic cells. Breaks down and is reformed each cell cycle (mitosis).

Question 3

What is the function of a microtubule and what are they composed of?

Answer 3

Function is for movement (cilia and flagellae). They mainly consist of tubulin.

Question 4

Where are microvilli found and what are their function?

Answer 4

Project from cell surface. Seen mainly in gut (absorpative) cells. There function is to increase surface area for absorption.

Question 5

What are the two types of endoplasmic reticulum?

Answer 5

Smooth (SER) and Rough (RER)

Question 6

What does the SER synthesise and what characterisitics does it possess?

Answer 6

Synthesises carbohydrates, lipids and steroids. Provides enzymatic degradation pathways and acts as a calcium reserve in muscle.

Question 7

What is the function of ribosomes?

Answer 7

Responsible for protein synthesis.

Question 8

What is the phospholipid bilayer?

Answer 8

Of the plasma membrane. Hydrophilic heads at periphery. Hydrophobic tails centrally orientated.

Question 9

What is the plasma membrane?

Answer 9

Defines the limits of the cell. Controls passage of materials from the inside and the outside of the cell.

Question 10

What is the structure and function of the mitochondria and where are they found?

Answer 10

Consists of an outer and an inner membrane which fold into cristae. The function is the site of fatty acid oxidations, citric acid cycle etc. Found wherever ATP (energy) is needed

Question 11

What is cytosol?

Answer 11

Cell fluid. Water, salts, protein etc.

Question 12

What is the function and the three subdivisions of cytoskeleton?

Answer 12

Function is to maintain the cells shape and internal organisation. Permits movement of substances within the cell.

1. Microtubules
2. Microfilaments (actins)
3. Intermediate filaments

Question 13

What is a cell?

Answer 13

The fundamental unit of life. Surrounded by a plasma membrane and consisting of protoplasm and organelles.

Question 14

What are the four plasma membrane specialisations?

Answer 14

1. Microvilli
2. Cilia
3. Microtubule
4. Specialised Cell Junctions

Question 15

What is the structure and function of the golgi apparatus?

Answer 15

Consists of flattened sacs, vesicles and vacuoles. Function is to process and package proteins from the ER into membrane bound secretory vesicles.

Question 16

What is the structure and function of the nucleolus organelle?

Answer 16

Composed of RNA, chromatin and protein. Function is the synthesis of rRNA for protein synthesis.

Question 17

Where is cilia found and what is its function?

Answer 17

Mainly found in the respiratory tract. The function is to move fluid over the cell surface.

Question 18

What is the role of nuclear pores?

Answer 18

Communication between the nucleus and cytoplasm

Question 19

What is the function of a cell junction and what are the three variations?

Answer 19

Function is for cell to cell communication and attachment.

1. Tight or occluding
2. Adhering
3. Gap