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progression Flashcards

1
Q

prophase

A

chromosomes condense causing them to thicken and therefore become visible. They appear as two sister chromatids held together by a centromere. The centrioles migrate to opposite poles of the cell and form spindle fibres. the nuclear envelope disintergrates

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2
Q

metaphase

A

spindle fibres attach to the centromeres. chromosomes (sister chromatids) line up on the equator

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3
Q

anaphase

A

the spindle fibres shorten. the centromere divides. chromatids are pulled to opposite poles of the cell

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4
Q

telophase

A

chromosomes uncoil and become longer, thinner. the nuclear membranes begin to form around the daughter nuclei

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5
Q

cytokinesis

A

cytoplasm and cell membrane divide to form two genetically identical daughter cells

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6
Q

when cytokinesis ends

A

interphase starts

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7
Q

what are the different stages of the cell cycle?

A

G1 (interphase), mitosis, cytokinesis, S-phase (DNA replication) and G2 (growth and production)

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8
Q

what is mitosis?

A

the division of the nucleas

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9
Q

what is interphase?

A

the cell prepares for mitosis by growing larger, replicating its organelles and synthesising DNA

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10
Q

what is s-phase?

A

the DNA is replicated so that two daughter cells can get one set of DNA. genetic material is checked here

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11
Q

G1

A

increases the size of the cytoplasm and cell. checks DNA for damage before replication

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12
Q

G2

A

is the second growth phase where duplicated DNA is error checked energy stores grow and cell size grows

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13
Q

Bacteria divide by binary fission, describe the process:

A

-replication of the circular DNA and plasmids
-increase in cytoplasm, cell membrane and ribosomes
-attachment of the DNA to the cell membrane
-the cell membrane pinch inwards to cause division of cytoplasm and membrane
-a new cell forms from the two molecules of DNA
-this produces two daughter cells, each with a single copy of circular DNA and variable number of plasmids

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14
Q

describe how viruses replicate

A

-attachment proteins on the virus bind to specific receptors on host cells
-endocytosis into the cytoplasm
-capsid removed
-viral genetic material released into cytoplasm
-DNA enters the nucleus (or RNA converted to DNA using reverse transcriptase)
-DNA replicated
-MRNA is made (copies of viral genes)
-MRNA is used to make viral proteins at a ribosome using the cells amino acids
-new virus assembled
–bud off cell membrane taking some of the membrane to form lipid envelope

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15
Q

why are antibiotic ineffective against viruses?

A

viruses do not have a cell wall that can be attacked by antibiotics
viruses do not perform protein synthesis, cell division

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16
Q

how do viruses cause disease

A

destroy/ damage the cells in which they replicate
they cause an immune response involving inflammation

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17
Q

what does the term partially permeable mean?

A

allow certain molecules to pass straight through but not others.

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18
Q

what kind of particles does the phospholipid bi-later allow to pass through?

A

small non polar molecules

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19
Q

what kind of molecules does the phospholipid not allow to pass through?

A

polar large molecules

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20
Q

what is the name of the model that describes cell membrane structure? why is it called that?

A

Fluid mosaic model. phospholipid molecules can move laterally which makes the membrane fluid. there are proteins which are scattered throughout the membrane which makes it look like a mosaic . Based on experimental and chemical evidence it is callused as a model.

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21
Q

components of fluid mosaic model

A

intrinsic proteins (span the phospholipid bilayer from one side to another) extrinsic proteins (embedded at the surface of bilayer) cholesterol, phospholipids (hydrophilic head interacting with the cytoplasm and hydrophobic tails facing away) glycolipids (carb covertly bonded to a lipid) glycoproteins ( carb chains attached to proteins)

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22
Q

difference between roles of intrinsic and extrinsic proteins

A

intrinsic act as channel and carrier proteins where’s extrinsic provide structural support, act as receptors for hormones or antigens, helps cell adhere

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23
Q

role of cholesterol

A

stabilises membrane as restricts movement of phospholipids (less fluid at high temps)
very hydrophobic prevents the loss of water

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24
Q

role of glycolipids

A

act as receptors
act as recognition sites
stability
helps cells attach

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25
Q

role of glycoproteins

A

act as receptors (hormones and nurotransmitters)
recognition sites
help cells attach, forming tissues

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26
Q

is facilitated diffusion active or passive?

A

passive, tie chary structure changed but no energy used

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27
Q

what are carrier proteins?

A

intrinsic proteins, change shape when molecules bind to them. this moves the molecule across the membrane and provides a pathway for large molecules

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28
Q

what are channel proteins?

A

provide a pathway for ions, fluid filled channels

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29
Q

what is water potential?

A

the tendency for water particles to move from one area to another by osmosis

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30
Q

hypotonic

A

low solute concentration in solution compared to inside the cell

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31
Q

hypertonic

A

high solute concentration in solution compared to inside the cell

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32
Q

isotonic

A

same solute concentration in solution as inside the cell

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33
Q

pure water

A

no solute very high conc of water particles so highest water potential with is 0

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34
Q

how does active transport work?

A

-the molecule to be moved binds to the carrier protein
-ATP binds to the carrier protein
-ATP is hydrolysed into ADP and Pi
-the Pi remains bound and causes a change in the tier chary structure
-the carrier changes shape and moves the molecule across the membrane
-Pi is released and the protein reverts back to original shape

35
Q

Exocytosis and endocytosis are passive or active?

A

active need ATP, provide a mechanism for bulk transport across cell membrane

36
Q

endocytosis

A

brings substances into the cell, the cell membrane pinch’s off to form a vesicle inside the cell

37
Q

exocytosis

A

brings substances into the cell, the vesicle fuses with the cell surface membrane

38
Q

if a cell has a membrane bound organelle it is a

A

Eukaryote

39
Q

organelles in making and secreting a protein

A

-the protein is assembled on the surface of rough ER by ribosomes
-the polypeptide passes into tubes of rough ER and is faded into secondary and terichary structure
-a vesicle containing the protein pinch of the rough ER and travels to Golgi
-in the Golgi the protein is modified and packaged into a vesicle
-the vesicle then moves the protein to the cell surface membrane
-the vesicle fuses with cell surface membrane by the process of exocuytopsis
note-mitochondria provide energy needed for the process in the form of ATP

40
Q

prokaryotic cell structure

A

cell membrane, 70s ribosomes, flagellum (enables movement) cell wall (murrain) capsule (slime layer outside the cell wall) circular DNA (not linaer or associated with histones)n plasmids, foo reserve and cytoplasm

41
Q

are viruses living

A

no they are a cellular

42
Q

preparing specimens for the light microscope

A

1)cut thinly
2)mount on the slide using mounted needle
3)apply a stain to increase contrast between different parts of the cell and make structures visible
4)apply coverslip to protect the lens and prevent the specimen drying out using a mounted needle to lower it

43
Q

calibrating a graticule

A

1)line up your eyepiece graticule up against the stage micrometer
2)count how many divisions on your graticule fall between two points on the stage micrometer
3) divide the value of one division on the stage micrometer by the number of divisions on the graticule to find pout what each graticule is worth record the number

44
Q

transmission

A

a beam of electrons is focused by magnetic lenses and passes through the specimen. a detector detects them on the other side

45
Q

scanning

A

a beam of electrons is fired and focused with magnetic lenses. the electrons bounce off the specimen and scatter. the pattern of scattering forms a 3D image on the surface

46
Q

cell fractionation

A

tissue is placed in a cold isotonic buffered solution (isotonic to keep water potential the same) homogenisation. filtration (remove cell and tissue debris) ultracentrifugation (remove supernatant and resin at a higher speed to pellet second most dense organelle)

47
Q

cancer

A

a tumour that has become malignant the cells have become de-deiferentiated and can break off and travel in blood/lymph to cause secondary cancers in other parts of the body

48
Q

where do cells spend most of there time?

A

interphase, if little time is spent there it is a sign of cancer (dividing uncontrollably)

49
Q

uncontrolled division can be stopped by

A

-targeting structures involved in cell division to prevent it eg spindle formation

50
Q

mutation in what gene causes uncontrolled cell division

A

P53

51
Q

how do mutations cause cancer?

A

change base sequence altering tie chary structure of proteins

52
Q

what are the different types of white blood cells Calle and are they specific or non-specific?

A

lymphocytes (specific)
phagocytes (non specific)

53
Q

what are antigens?

A

a foreign protein stimulating an immune response, resulting in antibody production

54
Q

where are antigens found?

A

-surface of pathogens
-surface of transplant cells
-abnormal body cells
-toxins

55
Q

what are the first lines of defence that pathogens coke across as they attempt to invade the body?

A

-mucus layer (nasal passages)
-enzyme production (tears)
-stomach acid
-cillia on epithelia cells to waft mucus away
-hairs
-blood clotting

56
Q

process of phagocytosis

A

1)receptors on phagocyte bind to antigen on pathogen
2)phagocyte engulfs pathogen and forms phagosome
3)lysosomes fuse with phagosome to form phagolysome to digest pathogen
4)breakdown products absorbed into cytoplasm or released by exocytosis
5)antigens displayed on phagocyte

57
Q

what kind of response are T-lymphocytes part of?

A

part of specific immune system response. carry out the cell mediated response

58
Q

what kind of response do B-lymphocytes form part of?

A

the humeral response, specific immune response

59
Q

function of B-lymphocytes

A

1)pathogens have cell surface antigen, or produce toxins that are antigens
2)each b-cell has different complimentary shaped receptor that binds to specific antigen
3) B cells divide by mitosis to form many clones, cloned b-cells differentiate to form plasma cells or b-memory cells
4) plasma cells then can be used to produce antibodies

60
Q

what are antibodies?

A

a globular protein, with quaternary structure specific to an antigen, produced and secreted by B-plasma cells

61
Q

what is specific about each antibody?

A

variable region has different tier chary structure

62
Q

what are the different ways in which antibodies combat pathogens?

A

Agglutoination (have two antigen binding sites, bound to two antigens causing them to agglutinate, this mobiles the pathogen)
-Neautralisation (toxin molecules are neutralised when antibodies bind to them because they no longer bind to host cells)
Enhacing phagocytosis (macrophage has receptors for the constant and region of the antibody, helps the macrophage engulf pathogen)

63
Q

what is the latent period?

A

the period of time between infection and symptom appearance

64
Q

what is the primary and secondary response?

A

primary- response to original infection
secondary-numerous memory cells in body

65
Q

why can we contract colds and flu more than once?

A

memory cells eventually die

66
Q

what are the risks associated with vaccines?

A

pain, sore arms and mild fevers

67
Q

object vaccinations

A

ethical reasons, don’t want side effects, conspiracy theories and religion

68
Q

active natural

A

infection with pathogen and long term

69
Q

active artificial

A

vaccinate with particular antigen and long term

70
Q

passive natural

A

mother to baby through placenta and short term

71
Q

passive artificial

A

infection of antivenon/ monoclonal antibody and short term

72
Q

what does HIV infect?

A

T-helper cells receptors

73
Q

what is retrovirus?

A

virus that has RNA

74
Q

when t-helper cells are infected?

A

a person suffers from a lot more diseases

75
Q

what does the term aids stand for and what actually is it?

A

acquired immunodeficiency syndrome. damaged immune system caused by progressive destruction of t-helper cells

76
Q

what must someone who is HIV positive take?

A

antiviral drugs, don’t occur during normal hormonal cell

77
Q

what are the four main ways that HIV is transmitted?

A

-transfusion of infected blood
-sharing needles
-infected semen
-maternal to foetal blood

78
Q

testing a bay from a HIV positive mother is inaccurate why?

A

virus may lay dormant for many years

79
Q

the process of HIV infection and replication?

A

1)attachment protein attach to complimentary receptor on surface of t-helper cell
2)capsid is released into cell, it uncoats to release RNA into cytoplasm
3)inside cell, reverse transcriptase, makes DNA from RNA
4)DNA remains inactive until DNA inserted into host cell DNA by enzyme intergrase
5)host cell is used to make viral proteins from viral DNA within the host cell DNA
6)Viral proteins assembled into new viruses which bud from cell, taking membrane and go infect other t-helper cells.

80
Q

what is a monoclonal antibody?

A

antibodies produced from a single clone of a plasma cell

81
Q

monoclonal antibodies in cancer treatment

A

used to direct chemotherapy drugs to specific tissues in the body

82
Q

crowns disease in cancer treatment

A

uses antibodies to bind to inflammatory chemicals such as cytokines to prevent them causing inflammation

83
Q
A

cells (6 decks)

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