Cell And Molecular Mt1

Front 1

Phylogenies

Back 1

how things change through time

Front 2

Model systems

Back 2

particular species that have been studied extensively and can be sued to answer questions/ serve as reference point

Front 3

cytology

Back 3

use of microscopes to study cell structure

Front 4

Anton Van Leewenhoek

Back 4

first to view life under microscope

Front 5

Hooke

Back 5

gave cells their names

Front 6

Louis pasteur

Back 6

discovered microorganisms are responsible for fermentation

Front 7

Postulates of the cell theory

Back 7

1. all living organisms are composed of one or more cells

2. the cell is the functional + structural unit of living organisms (activity of organism depends on total activity of the independent cells)

3. all cells arise from the division of pre-existing cells

Front 8

Ultramicroton slicing

Back 8

thin sectioning allows more light and there is less background tissue

Front 9

Fluid mosaic model

Back 9

membrane is dynamic, moves in fluid motion, substances are transported linearly

Front 10

Endosymbiont theory

Back 10

Lynn Margullis - mitochondria and chloroplasts used to be free-living cells

A single composite cell = two or more separate cells living in a symbiotic relationship

Front 11

Steps to Endosymbiont theory

Back 11

A. large anaerobic heterotrophic prokaryote ingested a small aerobic prokaryote

B. resisting digestion, the prokaryote took up residence as a permanent endosymbiont

-host cell reproduced with endosymbiont inside

-colony

-generations - evolution

-independent microbes -> modern day mitochondria

Front 12

key organizing features of cell structure

Back 12

1.matter: atoms, molecules, macromolecules

2. energy

3. organization - cell membrane

4. information

Front 13

Cytoplasm

Back 13

interior of cell organized into specific compartments

Front 14

Main characteristics of organisms

Back 14

1. Made of cells

2. Require energy

3. Reproduce

4. Maintain homeostasis

5. Organized

6. Respond to environment/stimuli

7. Grow and develop

8. Exchange materials with surroundings (water, wastes,gases)

Front 15

Genome

Back 15

hereditary material of the organism, all of its genes

-complete set of DNA in single cell organism

Front 16

Proteins

Back 16

large biological molecules - carry out various functions

-transport

-permeability

-degradation

-regeneration

Front 17

Why are proteins critical to the maintenance of the body?

Back 17

they make up and assist in...

-enzymes

-motion

-transport

-structure

-regulation

-protection

Front 18

proteomes

Back 18

all types and relative amounts of proteins made in a particular cell at specific time/conditions

-determine a cells structure and function

Front 19

Components of amino acid

Back 19

(At neutral pH)

amino group - positively charged

side chain

alpha-carbon

carboxyl group - negatively charged

Front 20

zwitterion

Back 20

an overall neutral molecule with a positive charge at one location and negative charge at a different location

Front 21

peptide bond

Back 21

a covalent bond between a carboxyl and amino group

Front 22

polypeptide

Back 22

ordered, covalently linked collection of amino acids

Front 23

Hierarchy of protein structure

Back 23

-primary: amino acid sequence of polypeptide

-secondary: determined by amino acid sequence and the chemistry of R groups

-alpha helix

-beta pleated sheet

-tertiary: complex 3D structure with hydro phobic/philic regions

-quaternary structure: the combined 3D structure of multimeric proteins

Front 24

5 factors influencing protein structure

Back 24

1. hydrogen bonds

2. ionic bonds

3. hydrophobic effect

4. disulphide bridge

5. Van der waals

Front 25

Steps in immune response

Back 25

1. pathogen enters body

2. antigen presenting cell engulfs intruder (phagocytosis)

3. dendritic cell migrates from skin to lymph node

4. presents antigen to T-cell

5. T-cell is activated

6. travels to site of pathogen

Front 26

MHC protein structure

Back 26

-external domains

-transmembrane domaine (hydrophobic)

-cytoplasmic tail (hydrophilic)

Front 27

peptide binding groove

Back 27

(taco shell - MHC and fillings - peptides)

Front 28

MHC 1

Back 28

-on all nucleated cells of the body

-present antigens that originate in cytosol

-present antigen to cytotoxic T-cells

Front 29

MHC 2

Back 29

-only on antigen presenting cells

-present antigens from extracellular spaces

Front 30

How do MHC's have the ability to present antigens from any potential source in life?

Back 30

1. peptide binding promiscuity

2. expression of several different MHC molecules on each cell

Front 31

polygenic

Back 31

the MHC region contains multiple genes with the same function, but slightly different structure

Front 32

[polymorphic

Back 32

occurence of more than one form (allele), each person has 2 forms of each MHC gene

Front 33

MHC 1 and 2 present to what part of T-cell

Back 33

1 - T-cytotoxic cell CD8

2 - T-helper cell CD4

Front 34

How do dendritic cells interact with helper T-cells?

Back 34

-dendritic cells travel to lymph nodes - present antigens to T-cells

-T-cell receptor - recognizes specific antigen

-helper T- cells with TCR specific for antigen on MHC2 molecules will bind to DC

-CD4 is a co-receptor that recognizes and binds to MHC2 molecules

Front 35

units of T-cell receptor

Back 35

-alpha and beta chains

-CD3 and zeta chains

-transcription factors

Front 36

Where is the MHC gene located

Back 36

chromosome 6 (HLA complex in humans)

Front 37

What maintains the diversity of MHC?

Back 37

pathogens/parasites - evolve resistance to MHC molecules

-hosts co-evolve

-pathogens - short generation times, large populations, many mutation - challenging for hosts

Front 38

What is the dissassortive mating hypothesis

Back 38

-males prefer females with dissimilar alleles (MHC complements own)

-females prefer males with heterozygote alleles (partner and offspring - able to fight off diseases)

Front 39

How is the structure of MHC molecules directly related to their function?

Back 39

charge and size, key active positions within the groove

Front 40

What is the significance of the 7000+ alleles expressed by the MHC

Back 40

diversity of pathogens - hosts need to be able to combat

Front 41

Biologists conducted skin grafts in cheetahs

-none were rejected - why?

Back 41

genetic bottleneck - reduction in variation - MHC's similar across species

(caused by reduction in population size)

Cheetahs -> more vulnerable to pathogens

Front 42

What are the implications of a larger proteome or compartmentalization?

Back 42

-specialization

-more complex internal organization

-more organelles/compartments

Front 43

organelle

Back 43

a structurally well-defined aggregate of macromolecules or membrane-bound compartments with its own unique structure and function

Front 44

What implications does cell size have?

Back 44

-the chemical activity in cell - require exchange of materials with environment

-upper limit on size - determined by ratio of cell's membranous surface (cell volume)

Front 45

benefits of an elaborate membrane system

Back 45

-increases functional surface area

-improves cell's ability to exchange materials with exterior

Front 46

how do the genome and proteome attain structure in cells

Back 46

genome - contains information that encodes the proteome

proteom - responsible for the distinctive structures and functions of living cells

Front 47

molecular machine

Back 47

moving parts - does useful work

e.i. flagella