Cells and proteins - 1

Question 1

What is a linear dilution?

Answer 1

consists of a range if dilutions that differ by an equal interval

Question 2

how are measurement errors reduced in a linear dilution?

Answer 2

each concentration is made individually so errors are reduced to only one concentration

Question 3

what is a log dilution?

Answer 3

range of dilutions that differ by a constant proportion

Question 4

how is a log dilution made up

Answer 4

each dilution solution is used as stock for the next dilution

Question 5

what is a colorimeter used for?

Answer 5

used to measure:

• the concentration of a pigment in a solution
• turbity of liquid
• density of cells in a culture

Question 6

what does a colorimeter record?

Answer 6

how much light is absorbed by a sample

Question 7

what is a standard curve used for?

Answer 7

to find an unknown concentration

Question 8

what is the purpose of a buffer?

Answer 8

to keep the pH of a solution at a nearly constant value

Question 9

what is centrifugation?

Answer 9

method for separating materials in suspension according to their density

Question 10

what is the liquid fraction of a tube called after centrifugation?

Answer 10

supernatant

Question 11

what technique is used to separate amino acids according to their solubility?

Answer 11

paper and TLC chromatography

Question 12

what is protein electrophoresis?

Answer 12

the use of a current flowing through a buffer to separate proteins

Question 13

what factors affect the rate of protein electrophoresis?

Answer 13

size and charge

Question 14

when does a protein have a net neutral charge?

Answer 14

at its isoelectric point

Question 15

what are antibodies?

Answer 15

naturally produced by white blood cells which targets microbes or other foreign cells for destruction

Question 16

what are antibodies shaped specifically to?

Answer 16

the antigen on the cell

Question 17

what is an antibody technique used for?

Answer 17

used for detection and identification of specific proteins

Question 18

what is utilised in antibody techniques?

Answer 18

the ability of antibodies to bind to a specific antigens

Question 19

what is a polyclonal antibody?

Answer 19

a serum made with many different antibodies against an antigen

Question 20

what is immunohistochemical staining used for?

Answer 20

used to detect specific antigens in cells based on an antigen-antibody reaction

Question 21

what is protein blotting?

Answer 21

when different types of antibodies are blotted onto gel with proteins

Question 22

what produces antibodies?

Answer 22

B lymphocytes

Question 23

what is an immunoassay technique such as an ELISA used for?

Answer 23

used for diagnosis and detection of disease

Question 24

what is involved in an immunoassay?

Answer 24

• use of monoclonal antibodies that have an enzyme attached

- a reporter enzyme catalyses a colour change when an antigen interaction is present

Question 25

what are monoclonal antibodies?

Answer 25

supply of antibodies that are identical and will bind to the exact same feature of the antigen

Question 26

when making monoclonal antibodies, what fuses the B lymphocytes and myeloma cells together?

Answer 26

polyethylene glycol

Question 27

what are produced when B lymphocytes and myeloma cells fuse together?

Answer 27

hybridomas

Question 28

what is a cell culture?

Answer 28

when cells are grown under aseptic techniques

Question 29

what is a benefit of a cell culture?

Answer 29

can produce many genetically identical clones of an initial cell sample

Question 30

why must aseptic techniques be followed?

Answer 30

to help prevent contamination

Question 31

state some aseptic techniques

Answer 31

- wearing a lab coat - washing hands - using an autoclave - using a Bunsen burner to sterilise wired loops and prevent air borne organisms

Question 32

what nutrients are required to grow mammalian cells?

Answer 32

- glucose - growth factors, e.g - foetal bovine serum - vitamins - salts - amino acids

Question 33

what four steps are involved in the culturing of mammalian cells?

Answer 33

- adhesion - spreading - divison - confluence

Question 34

why are cancer (myeloma) cells good for research?

Answer 34

immortal and so unlimited life span

Question 35

what two main methods are used for plant tissue culture?

Answer 35

explants and hybridisation

Question 36

what is an explant?

Answer 36

small pieces of plant tissue that are placed on a solid medium

Question 37

what is a haemocytomter?

Answer 37

a graduated micro slide used to count cell density