Cells - Week 2

Question 1

What Are Cells?

Answer 1

• Smallest living unit of an organism.
• Made up of chemicals – atoms and molecules
• Similar cells combine to make tissues.

Question 2

What are components of Cells called?

Answer 2

Organelles

Question 3

What do Organelles do?

Answer 3

Organelles determine a cells function and ability to contribute to the activity of tissues and organs.

Question 4

What are the two general classes of cells?

Answer 4

1. Sex Cells – Ovum and Sperm
2. Somatic Cells- every other cell in the body

Question 5

What are the main components of a Somatic Cell?

Answer 5

1. Plasma Membrane – Outer Boundary
2. Cytoplasm – everything between the nucleus and the plasma membrane
3. Nucleus – Control Centre

Question 6

What are the two terms that are commonly used to describe the regions of cells?

Answer 6

1. INtracellular - refers to everything inside the cell
2. EXtracellular - refers to everything outside the cell

Question 7

What does Intracellular refer to?

Answer 7

Everything inside the cell

Question 8

What does Extracellular refer to?

Answer 8

Everything outside the cell

Question 9

What does Cytoplasm consist of?

Answer 9

1. Cytosol - fluid inside the cell (dissolved ions, nutrients, proteins, and waste products of the cell)
2. Organelle – the different structures inside the cell

Question 10

What is the Cytosol?

Answer 10

Cytosol is fluid inside cell containing dissolved ions and nutrients, proteins, and waste products.

Location: In the Cytoplasm

Appearance: Fluid that occupies at least 50% of a cell’s volume.

Consist of: Most of the cytosol is water, but proteins, sugars, amino acids and ions are also present.

Function: Where most of the chemical reactions occur in a cell

Question 11

What is the Plasma Membrane?

Answer 11

The plasma membrane is the physical barrier between the intracellular environment (cytoplasm) and the extracellular environment.

Question 12

What is the function of the Plasma Membrane?

Answer 12

It’s responsible for regulating the exchange of substances between the Intracellular (inside cell) and Extracellular (outside cell) environments.

It also provides structural support.

Question 13

What is the composition of Plasma Membrane?

Answer 13

• 42% Lipids (Fat)
• 5% Proteins
• 3% Carbohydrates

Question 14

What does Hydrophobic mean?

Answer 14

Water fearing

Question 15

What does Hydrophillic mean?

Answer 15

Water loving

Question 16

What is the Phospholipid bylayer in a Plasma Membrane?

Answer 16

Phospholipid is made up of lipid (fat) and form a bilayer (double layer)

It consists of two long hydrophobic chains (black) linked to hydrophilic phosphate head (yellow)

Hydrophillic phosphate (heads) is on the top and bottom exterior surface (water loving)

Hydrophobic chains (links) are in the interior surface (fearful of water)

Question 17

What are the two types of Proteins and their function in the Plasma Membrane?

Answer 17

Integral proteins (or transmembrane proteins) – large proteins that span the entire thickness of the plasma membrane
Function can be RECEPTORS, CARRIERS, OR CHANNELS.

Peripheral proteins – Small proteins found on the inner or outer surface of the membrane
Function TO ANCHOR ENZYMES.

Question 18

What are Carbohydrates function in the Plasma Membrane?

Answer 18

3% Carbohydrates

Form complex molecules such as glycolipids, and glycoproteins.

Function in LUBRICATION, PROTECTION, ANCHORING, AND CELL MOVEMENT

Question 19

What are the 11 Organelle Structures and their functions?

Answer 19

1. Mitochondrion - produces ATP - the energy for the cell.
2. Smooth endoplasmic reticulum - produces fats and steroid hormones.
3. Ribosomes - makes protein
4. Rough endoplasmic reticulum - protein production and runs quality-control and dispatch with the proteins.
5. Golgi Apparatus - modifies, sorts, and packages the proteins ready for secretion.
6. Peroxisomes - break down fatty acids.
7. Secretory vesicles - store molecules and proteins until they’re ready to be released by the cell.
8. Lysosomes - involved in digestion and waste removal.
9. Centrioles - help with cell division.
10. Microtubules - play a structural role in maintaining cell shape.
11. Nucleus - control center of the cell. It contains the DNA for every protein that the cell produces.

Question 20

What is Mitochondria?

Answer 20

It produces ATP (the energy for the cell)

Scattered throughout the cytoplasm, but localised where maximum energy is required

Function: Produces most of a cell’s ATP, which is the energy source of the cell

Question 21

What is Smooth Endoplasmic Reticulum?

Answer 21

Produces fatty acids, steroid hormones (estrogen and testosterone) and enzymes (detoxify alcohol or drugs).

Extends from the rough endoplasmic reticulum

Question 22

What is Ribosomes?

Answer 22

Makes protein for the cell’s own use.

Can be attached to rough endoplasmic reticulum or free floating in the cell.

Question 23

What is the Rough Endoplasmic Reticulum (RER)?

Answer 23

Involved with protein production for export from the cell. It folds, runs quality control and dispatch with proteins.

Continuous with outer membrane of the nuclear envelope.

Question 24

What is Golgi apparatus?

Answer 24

Modifies, sorts and packages proteins ready for secretion.

Usually adjacent the nucleus and RER

Function / Process:
1. The convex side of the Golgi apparatus (known as the entry or ‘cis’ face) receives newly synthesised proteins from the rough endoplasmic reticulum.

2. The concave side (exit or ‘trans’ face) is where proteins leave the Golgi apparatus.
3. As proteins pass through the Golgi apparatus, they are concentrated and chemically modified by the addition of lipids and/or carbohydrate molecules.
4. Modified proteins leave the Golgi apparatus via secretory vesicles.

Question 25

What is Peroxisomes?

Answer 25

Break down fatty acids

Scattered throughout cytoplasm

Question 26

What are Secretory vesicles?

Answer 26

Transports molecules and proteins from the Golgi apparatus to the exterior of the cell and stores them until they’re ready to be released by the cell.

Accumulate between Golgi apparatus and plasma membrane where material is released from the cell.

Question 27

What are Lysosomes?

Answer 27

Involved in digestion and waste removal.

Scattered throughout the cytoplasm

Contain a variety of digestive enzymes that breakdown old and damaged cellular components, as well as ingested foreign material such as bacteria.

Question 28

What are Centrioles?

Answer 28

Helps with cell division

Near the nucleus

Synthesises microtubules and plays an important role in cell division

Question 29

What are Microtubules (or cytoskeleton)?

Answer 29

Form the internal framework of a cell.
Give a cell its strength, shape and support also aids in cell division.
They also transport organelles, vesicles, granules and chromosomes through the cell.

Scattered throughout the cytoplasm

Question 30

What is the Nucleus?

Answer 30

Control centre of the cell containing DNA, that forms genes which direct all of the activities of the cell.

Usually found in the centre of the cell

Question 31

Name the different Organelle structures on the diagram

Answer 31