Cell Biology

Question 1

What are the 4 main elements that make up cells?

Answer 1

Carbon, Oxygen, Nitrogen and Hydrogen

Question 2

What is cytoplasm made up of?

Answer 2

Cytosol (fluid)
Organelles
Inclusions (chemical substances)

Question 3

Name the 5 organelles that are membranous

Answer 3

1. Nucleus
2. Endoplasmic Reticulums
3. Golgi Apparatus
4. Lysosome
5. Mitochondria

Question 4

What is the function of the nucleus?

Answer 4

Contains DNA for the cell as well as chromatin and proteins

Question 5

What is the function of the nucleolus?

Answer 5

Synthesises and assembles ribosomes (contains RNA)

Question 6

What is the function of the rough endoplasmic reticulum?

Answer 6

Transports proteins made by attached ribosomes

Question 7

What is the function of the smooth endoplasmic reticulum?

Answer 7

Synthesises and transports lipids and steroids

Question 8

What is the function of the ribosomes?

Answer 8

Site of protein synthesis

Question 9

What is the function of the golgi apparatus?

Answer 9

Modifies and packages proteins

Question 10

What is the function of peroxisomes?

Answer 10

Break down fatty acids and convert hydrogen peroxide to water

Question 11

What is the function of lysosomes?

Answer 11

Destroy harmful enzymes, worn out organelles and foreign substances

Question 12

What is the function of proteasomes?

Answer 12

Destroy unneeded or damaged proteins

Question 13

What is the function of mitochondria?

Answer 13

Site of aerobic respiration; production of ATP

Question 14

Name the 4 types of passive transport

Answer 14

1. Simple diffusion
2. Facilitated diffusion
3. Filtration
4. Osmosis

Question 15

Name the 4 types of active transport

Answer 15

1. Exocytosis
2. Endocytosis
3. Pinocytosis
4. Phagocytosis

Question 16

What is simple diffusion?

Answer 16

Movement of lipid-soluble molecules from an area of high concentration to an area of low concentration (down the concentration gradient) across a semi-permeable membrane

Question 17

What factors affect simple diffusion?

Answer 17

1. Concentration gradient
2. Distance of travel
3. Surface area
4. Thickness of surface
5. Temperature

Question 18

What is facilitated diffusion?

Answer 18

Movement of lipid-insoluble molecules from an area of high concentration to an area of low concentration (down the concentration gradient) across a semi-permeable membrane

Question 19

Describe channel proteins

Answer 19

Each is specific to one type of molecule and has a gate-like structure that open when complementary molecules bind to it

Question 20

Describe carrier proteins

Answer 20

Large polar molecules bind to these proteins which then change shape and release molecules on the other side of the membrane

Question 21

What is osmosis?

Answer 21

Movement of molecules from an area of high water potential to an area of low water potential (down the water potential gradient) across a semi-permeable membrane

Question 22

What is water potential?

Answer 22

Low concentration = more potential for water to move into the space

Question 23

Explain the 3 different types of water potential distribution in solutions

Answer 23

Isotonic = equal water potential
Hypertonic = water potential lower outside = water moves out (can lead to crenation)
Hypotonic = water potential lower inside = water moves in (can lead to haemolysis)

Question 24

What is active transport?

Answer 24

Movement of molecules from an area of low concentration to an area of high concentration (against the concentration gradient)

Question 25

What is filtration?

Answer 25

Movement of water and solutes across the plasma membrane in the cardiovascular system due to hydrostatic pressure

Question 26

What is exocytosis?

Answer 26

Getting rid of waste products after being transported in a vesicle

Question 27

What is endocytosis?

Answer 27

Substances moving into the cell in vesicles

Question 28

What is phagocytosis?

Answer 28

Solid substances are engulfed by vesicles to be digested

Question 29

What is pinocytosis?

Answer 29

Liquid substances are engulfed by vesicles to be digested

Question 30

Outline the process of DNA replication

Answer 30

1. Hydrogen bonds break by DNA helicase and double helix structure unwinds 2. Exposed bases bind with free nucleotides by DNA polymerase 3. Sugar phosphate backbone joins to new strand of DNA by DNA polymerase 4. 2 identical strands of DNA are created and return to a double helix structure

Question 31

Briefly outline what occurs in Interphase

Answer 31

- DNA replication | - Cell growth

Question 32

Briefly outline what occurs in Prophase

Answer 32

- Chromatin condenses into chromosomes - Centrioles move to opposite poles - Spindles develop - Sister chromatids pair up

Question 33

Briefly outline what occurs in Metaphase

Answer 33

- Chromosomes gather at the equator | - Spindles attach to centromeres

Question 34

Briefly outline what occurs in Anaphase

Answer 34

- Spindles contract | - Centromere splits and chromatids are pulled to opposite poles

Question 35

Briefly outline what occurs in Telophase

Answer 35

- Chromatids uncoil and lengthen - Nucleolus and nuclear membrane reform - Spindles break down and centrioles replicate

Question 36

Give 3 areas of healthcare in which mitosis is significant

Answer 36

1. Tissue repair 2. Disease inheritance 3. Assistance of reproduction (IVF, genetic engineering)

Question 37

What is apoptosis?

Answer 37

Death of cells

Question 38

What are eukaryotic cells?

Answer 38

Cells containing a nucleus and membrane-bound organelles

Question 39

What are prokaryotic cells?

Answer 39

Cells containing no nucleus

Question 40

What is an organelle?

Answer 40

A structure in a cell that has a role in the cell's functioning

Question 41

What does cytotoxic mean?

Answer 41

Something that damages/ destroys living cells