3.1 understanding principles of cancer

Question 1

what is cancer?

Answer 1

• abnormal cell division
• alteration of cell cycle

Question 2

what are the 3 stages of the cell cycle

Answer 2

1. interphase- (3 phases- gap 1, synthesis, gap 2)
2. mitosis (cell divides- 3 stages)
3. G0 stationary phase (cells in G0 have specialised- no further changes occur)

Question 3

what are the stopping cells

control of the cell cycle

Answer 3

• proteins
• genes code for proteins

Question 3

what do stopping proteins do

control of the cell cycle

Answer 3

• either breakdown or ar modified by cellular processes to allow the cycle to continue
• regulates the speed at which cells can divide
• can stop cell division from ever occuring

Question 4

what are DNA repair genes

control of the cell cycle

Answer 4

• genes that check and repair DNA when it is being synthesised (replication)
• they stop mutations from occuring- avoiding cancer

Question 4

results of mutations

Answer 4

• abnormal cell division
• alteration of cell cycle
• uncontrolled proliferation of cells

Question 4

what is Apoptosis?

Answer 4

• programmed cell death
• cells with damaged DNA are potential sources of cancer
• old, altered cells with unfixable DNA are targeted by the body for destruction
• breaks down cells into their component molecules

Question 4

proto oncogenes

Answer 4

cancerous cells that have acquired a series of mutations

Question 4

why is abnormal cell division a multi-step process

Answer 4

where multiple mechanisms must fail before a cell becomes cancerous.

Question 5

list the proto ocogenes of cancerous cells

Answer 5

1. make them divide more quickly
2. allows them to escape controls on cell division
3. damages the DNA repair mechanisms
4. allows them to avoid programmed cell death

Question 6

primary cancer

Answer 6

where the cancer starts

Question 7

secondary cancer

Answer 7

• when cancer cells break away from primary cancer via bloodstream and lymph
• a new cancer growth
• still the same cell type as primary cancer

Question 8

differences between cancer cells and normal cells

Answer 8

• normal cells: controlled growth, specialised cells, even appearance, even shaped nuclei, organised arrangement
• cancer cells: contact inhibition, undifferentitated, variable appearance and shape, disporganised arrangement.

Question 9

features of cancer cells

Answer 9

• grow and divide at an abnormally rapid rate
• are poorly differentiated
• have abnormalites in their: membranes, cytoskeletal proteins, morphology

Question 10

types of cancerous tumours

Answer 10

• Carcinoma;
• Sarcoma;
• Leukaemia;
• Lymphoma;
• Melanoma.

Question 11

benign tumour

Answer 11

Non-invasive tumours; not considered to be cancer.

Question 12

carcinoma cancer

Answer 12

type of cancer that starts in cells that make up the skin or tissie lining the organs. e.g. liver or kidney

Question 13

sarcoma cancer

Answer 13

rare cancers that develop in the muscle, bone, nerves, cartilage, tendons, blood vessels and the fatty and fibrous tissues.

Question 14

leukaemia

Answer 14

is any type of cancer that affects the blood and bone marrow where blood cells are made e.g. Acute myeloid leukaemia

Question 15

lymphoma

Answer 15

any type of blood cancer that develops from lymphocytes (a type of white blood cell). E.g Non Hodgkin and Hodgkin lymphomas

Question 16

melanoma

Answer 16

any type of cancer that develops from the pigment-containing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye. E.g. ocular melanoma

Question 17

malignant tumour

Answer 17

An invasive tumour that can spread around the body; true cancer