Biology Topic 1: Cells

Front 1

How big is one micrometer? (C1.1)

Back 1

One micrometer is equal to one thousandth of a millimeter.

Front 2

What is a unicellular organism? Give an example. (C1.1)

Back 2

A unicellular organism is an organism that consists of only one cell. e.g. bacteria, and yeast

Front 3

What is a multi-cellular organism? give an example. (C1.1)

Back 3

A multi-cellular organism is an organism that consists of a large numbers of specialised types of cells. e.g. plants and animals

Front 4

What are 9 life processes of a cell? (C1.1)

Back 4

1. Maintaining a stable intracellular environment

2. Controlled exchange of materials between the intracellular and extracellular environments

3. Detection and response to stimuli

4. Obtaining and transforming energy for use through cell respiration

5. Breakdown and synthesis of macro-molecules

6. Cell division

7. Growth and development

8. Movement

9. Reproduction

Front 5

What do you call the size of an objects external surface? (C1.2)

Back 5

Surface Area.

Front 6

What do you call the 3D space an object occupies? (C1.2)

Back 6

Volume.

Front 7

Calculate the surface area, volume, and SA:V ratio of a cube with sides of 2cm. (C1.2)

Back 7

SA - 2x2x6 = 24 (cm squared)

V - 2x2x2 = 8 (cm cubed)

SA:V - 24/8 = 3

Front 8

Which cell has the greater SA:V ratio? (C1.2)

Back 8

Cell 1.

Front 9

Does a daughter cell have a slightly greater, or slightly smaller SA:V ratio than the parent cell? (C1.2)

Back 9

Slightly greater.

Front 10

What are the two types of cells? (C2.1)

Back 10

Prokaryote and Eukaryote.

Front 11

What structural similarities do Prokaryote and Eukaryote cells share? (C2.1)

Back 11

Both have a cell membrane, both have a cytoplasm, both have 'free' ribosomes.

Front 12

What are the structural differences between Prokaryote (P) and Eukaryote (E) cells? (C2.1)

Back 12

In P DNA is in the cytoplasm (there is no nucleus), in E the DNA is in the nucleus.

P have one circular chromosone, E have many linear chromosones.

P have naked DNA, E have non-naked DNA.

P lack membrane-enclosed organelles, E have membrane-enclosed organelles.

P may have plasmids, all E lasck plasmids.

P are less complex, E are more complex.

Front 13

What is the function of the nucleus? (C2.2)

Back 13

The nucleus directs protein synthesis by synthesising messenger RNA according to gentetic instructions provided by the DNA that it houses.

Front 14

What is the function of the rough Endoplasmic Recticulum (ER)? (C2.2)

Back 14

The rough ER is a site of protein synthesis. It also modifies proteins destined for export out of the cell (or secretory proteins) and forms vesicles so that they can be transported to the Golgi Body.

Front 15

What is the function of the smooth ER? (C2.2)

Back 15

The smooth ER is the site of lipid synthesis.

Front 16

What is the function of the Golgi Body? (C2.2)

Back 16

The Golgi Body is a stack of membranes that completes modification of proteins and forms vesicles to transport them to the cell membrane for secretion to the extracellular environment.

Front 17

What is the function of the Mitochondrion? (C2.2)

Back 17

Mitochondrion is the site of most of the stages of aerobic respiration, which is the metabolic pathway that breaks down large molecules to release energy for ATP synthesis.

Front 18

What is the function of the Chloroplast? (C2.2)

Back 18

Chloroplasts contained chlorophyll and are the sites of photosynthesis, which is the process o turning light energy into chemical energy.

Front 19

What is the function of the Vacuole? (C2.2)

Back 19

The vacuole is used in plant cells to store ions, to maintain turgidity and dispose of substances before they disrupt the intracellular environment.

Front 20

What membrane-enclosed organelles have double membranes? (C2.2)

Back 20

1. The nucleus.

2. Mitochondrion.

3. Chlorplasts.

Front 21

What is endocytosis? (C3.2)

Back 21

Endocytosis is the uptake of large molecules using vesicles (by some eukaryote cells). For example a protein or cholesterol in animal cells.

Front 22

Is endocytosis an active process? (C3.2)

Back 22

Yes, meaning that it needs energy from ATP be to be carried out.

Front 23

What is exocytosis? (C3.2)

Back 23

The secretion (or export) of large molecules using a vesicle (by some eukaryote cells). For example when a protein is transported out of an animal cell.

Front 24

Is exocytosis an active process? (C3.2)

Back 24

Yes, meaning that it needs energy from ATP be to be carried out.

Front 25

Name three functions of the cytoskeleton with examples. (C3.3)

Back 25

1. The maintenance of cell shape; for example in red blood cells.

2. Anchors and moves organelles; for example chlorplasts in leaves.

3. Moves the cell membrane; for example during exocytosis.

Front 26

What is the intracellular environment? (C4.1)

Back 26

The chemical composition and temperatue of the cytoplasm.

Front 27

What is the extracellular environment? (C4.1)

Back 27

The chemical composition and temperature of the environment surrounding the cell.

Front 28

Why does the intracellular environment need to be kept stable? (C4.2)

Back 28

So that enzymes that catalyse steps in metabolic pathways are not disrupted.

So that metabolic pathways will be able to proceed efficiently and at their optimum rate.

Cells will function normally.

Front 29

Materials are selected for exchange at the cell membrane on the basis of... (C4.3)

Back 29

1. Size

2. Solubility

3. Charge

4. Molecular recognition

5. Availability of energy

Front 30

Does passive transport require energy? (C5.1)

Back 30

No.

Front 31

Give three examples of passive transport. (C5.1)

Back 31

1. Osmosis

2. Simple Diffusion

3. Facilitated Diffusion

Front 32

What is Osmosis? (C5.1)

Back 32

Osmosis is the net movement of water across a semi-permeable membrane from a region of low solute concentration to a region of high solute concentration until equilibrium is reached.

Front 33

What is simple diffusion? (C5.1)

Back 33

Simple diffusion is the net passive movement of a substance across a semi-permeable membrane from a region of high solute concentration to a region of low solute concentration until equilibrium is reached.

Front 34

What is facilitated diffusion? (C5.1)

Back 34

Facilitated diffusion is the net diffusion of a substance across a membrane with the aid of a membrane transport protein.

Front 35

What is a hypotonic region? (C5.1)

Back 35

A region of low solute concentration.

Front 36

What is a hypertonic region? (C5.1)

Back 36

A region of high solute concentration.

Front 37

What is active transport? (C5.2)

Back 37

Active transport is the movement of substances against the concentration gradient with the expenditure of energy.

Front 38

What are the three main energy uses of cells? (C6.1)

Back 38

1. Movement

2. Synthesis

3. Maintenance of a stable intracellular environment

Front 39

Energy is transferred to the Earth from the sun in physical form as what? (C7.1)

Back 39

Heat energy and Light energy.

Front 40

What is heat energy used for? (C7.1)

Back 40

Heat energy ensures that the Earths surface temperature remains suitable for life.

Front 41

What is light energy used for? (C7.1)

Back 41

Light energy that strikes plants is used for photosynthesis.

Front 42

What is the name used for organisms that photosynthesise? (C7.1)

Back 42

Autotrophs.

Front 43

Autotrophs obtain energy directly from the environment in physical form as light energy and transform it into what? (C7.1)

Back 43

Stored chemical energy.

Front 44

What is the name for organisms that do not photosynthesise? (C7.1)

Back 44

Heterotrophs.

Front 45

How do heterotrophs obtain energy? (C7.1)

Back 45

From autotrophs or other heterotrophs through food webs.

Front 46

What is the word equation of photosynthesis? (C7.2)

Back 46

Carbon Dioxide + Water = Glucose + Oxygen

Front 47

What is the chemical equation of photosynthesis? (C7.2)

Back 47

6CO2 + 6H20 = C6H12O6 + 6O2

Front 48

What percentage of energy is captured in ATP during aerobic cell respiration? (C7.3)

Back 48

Approximatley 40%

Front 49

What percentage of energy leaves the cell as heat during aerobic cell respiration? (C7.3)

Back 49

Approximatley 60%

Front 50

What is the word equation for aerobic cell respiration? (C7.3)

Back 50

Glucose + Oxygen = Carbon Dioxide + Water

Front 51

What is the chemical equation for aerobic cell respiration? (C7.3)

Back 51

C6H12O6 + 6O2 = 6CO2 + 6H20

Front 52

What is the equation for the conversion of ATP to ADP? (C7.4)

Back 52

ATP = ADP + P + Free energy

Front 53

What is the equation for the conversion of ADP to ATP? (C7.4)

Back 53

ADP + P + Free energy = ATP

Front 54

What is a metabolic pathway? (C7.5)

Back 54

A process that involves a specific sequence of many metabolic reactions or 'steps'.

Front 55

What are the factors that can alter a step in a metabolic pathway? (C7.6)

Back 55

1. Temperature can be below or above the optimum level.

2. pH conditions outside of the optimum pH.

Front 56

Each step in a metabolic pathway includes... (C7.7)

Back 56

1. The production of a compound that is a substrate for other metabolic pathways.

2. Some energy loss as heat.

Front 57

Why does a cells DNA replicate before it divides? (C8.1)

Back 57

So that each daughter cell receives a genetically identicall copy of the parents DNA.

Front 58

What is the process that prokaryote cells divide by? (C8.2)

Back 58

Binary Fission.

Front 59

What is the process eukaryote cell divide by? (C8.3)

Back 59

Mitosis followed by cytokinesis.

Front 60

What are the stages of mitosis? (C8.3)

Back 60

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

Front 61

What are the four stages of interphase? (C9.1)

Back 61

G0, G1, S phase, G2

Front 62

Describe the G0 stage. (C9.1)

Back 62

The non-dividing state of the cell, when it is carrying out its function.

Front 63

Describe the G1 stage. (C9.1)

Back 63

When the cell produces gene products (for example by carrying out protein synthesis) and new organelles (like mitochondrion and chloroplasts), and grows.

Front 64

Describe S phase. (C9.1)

Back 64

When the cell carries out DNA replication to produce two genetically identical copies of it's DNA.

Front 65

Describe the G2 stage. (C9.1)

Back 65

When the cell makes final preperations for cell division.

Front 66

Where are the three 'checkpoints' during interphase that regulate the cell cycle. (C9.1)

Back 66

The G1 checkpoint

The G2 checkpoint

The M checkpoint

Front 67

What does the G1 checkpoint assess and trigger? (C9.1)

Back 67

Assesses whether the DNA is damaged. If DNA is not damaged a go ahead signal will trigger DNA replication

Front 68

What does the G2 checkpoint assess and trigger? (C9.1)

Back 68

Assesses whether DNA replication has occured. If DNA replicatio has occured then a go ahead signal will trigger mitosis to complete up until the end of metaphase.

Front 69

What does the M checkpoint assess and trigger? (C9.1)

Back 69

Assesses whether DNA replicatio has occured correctly, if so it will trigger the completion of mitosis.

Front 70

What are the internal factors involved in cell cycle regulation? (C9.1)

Back 70

Gene products.

Front 71

What does MPF stand for? (C9.1)

Back 71

Maturation-Promotion Factors

Front 72

What gene product and enzyme combine to form MPF's? (C9.1)

Back 72

Gene Product: Cyclins

Enzyme: CDK

Front 73

What does CDK stand for? (C9.1)

Back 73

Cyclin-dependent Kinases

Front 74

Name one way that MPF's give the 'go-ahead' signal at the G2 checkpoint. (C9.1)

Back 74

The increase of MPF's is the 'go-ahead' signal for the cell to start mitosis through to the end of metaphase.

Front 75

Name one way that MPF's give the 'go-ahead' signal at the M checkpoint. (C9.1)

Back 75

The decrease of MPF's the 'go-ahead' signal for the cell to resume mitosis through to the end of telophase.

Front 76

Name one other internal factor that is able to regulate the cell cycle. (C9.1)

Back 76

The gene p53 can give the stop signal at the G1 checkpoint.

Front 77

List four external factors that affect the cell cycle. (C9.1)

Back 77

1. Surface Area to Volume Ratio

2. Nutrient Levels

3. Cell Density

4. Substrate Anchorage

Front 78

Explain how Nutrient Levels can serve as a 'stop' signal. (C9.1)

Back 78

If the level of nutrients in the tissue fluid falls to a critical minimum, the cell cycle stops.

Front 79

Explain how Cell Density can serve as a 'stop' signal. (C9.1)

Back 79

When the space between cells reaches a critical minimum, the cell cycle stops.

Front 80

Explain how Substrate Anchorage can serve as a 'stop' signal. (C9.1)

Back 80

Once a single layer of cells has covered a surface (or substrate), the cell cycle in all of the cells in that layer stops.

Front 81

What is a mutation? (C9.3)

Back 81

A random or induced change in the sequence of nucleotides in a gene.

Front 82

What is the name for chemicals that cause mutations? (C9.3)

Back 82

Carcinogens.

Front 83

List three ways carcinogens upset the checkpoint controls that regulate the cell cycle. (C9.3)

Back 83

1. By causing harmful mutations in genes that regulate cell division.

2. By having a 3D structure similar to gene products involved in the control of cell division which allows them to mimic their actions.

3. Acting as chemical inhibitors and blocking, for example, the binding of substrates to enzymes in the production of gene products involved in cell regulation.

Front 84

List three treatments of cancer. (C9.3)

Back 84

1. Surgery.

2. Radiotherapy.

3. Chemotherapy.

Front 85

Give five pieces of evidence suggesting that prokaryote cells existed before eukaryote cells. (C10.1)

Back 85

1. Fossils of prokaryotic cells have been found 2 billion years older than any eukaryote cells.

2. Mitochondrion and chloroplasts carry DNA separate from the nucleus.

3. Mitochondrion and chloroplasts have their own ribosomes similar to that of prokaryote cells.

4. Mitochondrion and chloroplasts can replicate independently.

5. Mitochondrion and chloroplasts have double membranes, and the inner membrane resembles that of a prokaryote cell.

Front 86

What is endosymbiosis? (10.2)

Back 86

The mutually beneficial (or symbiotic) relationship between two cells.

Front 87

List 6 points about a cell culture medium that most be controlled or monitored. (C11.1)

Back 87

1. Culture medium must be sterile.

2. Temperature must be optimum.

3. pH levels must be optimum (and osmotic conditions)

4. Optimal levels of nutrients (such as glucose and amino acids)

5. Addition of growth hormones when needed

6. Monitoring of cell density

Front 88

List 6 uses for cell culturing. (C11.1)

Back 88

1. Production of medical drugs

2. Drug testing

3. Cancer research

4. Reconstructive surgery

5. Growing clones of plants for agriculture (for example selectivity bred plants that have been genetically engineered)

6. Producing cultured meat

Front 89

List three ethical questions on the topic of cell culture. (C11.1)

Back 89

1. Is it right to manipulate people cells in this way? And to what extent should it be permitted?

2. Should donors be paid for using cells, or be permitted to use payment as an income stream?

3. Human cell culture means not culturing cells of other animals, so shouldn't it be encouraged?

Front 90

List four ways chemicals can interfere with cell metabolism. (C12.1)

Back 90

1. Disrupt a cells ability to maintain a constant internal environment.2. Inhibit an enzyme and thus block a specific step in a metabolic pathway.3. Induce a mutation in a gene and thus prevent the synthesis of protein.4. Mimic the action of a growth protein and disrupt the control of the cell cycle.