Micro exam final

mutation

change in base sequence pf DNA, change in protein, can be harmful, beneficial, or neutral

point mutation

singe base pair substitution

missense mutation

base pair substitution

nonsense mutation

create stop codon

frameshift mutation

one or more base pairs in DNA inserted/deleted

recombination

combining DNA from different sources of recombinant DNA

genetic changes thorugh

natural and artificial selection, genetic engineering

vertical gene flow

parents to progeny sexual reproduction, doesn’t exist in bacteria

horizontal gene flow

genes transferred from one mature independent organism to another, bacteria, through transformation, transduction, or conjugation.

transformation

uptake of naked DNA

griffith’s experiment

1920s, streptococcus pneumoniae, encapsulated strain (S) caused pneumonia while non-encapsulated (R) did not cause pneumonia, combined d s strain with living r strain to make s strain

competence

ability to take up DNA and become transformed, some bacteria naturally competent like bacillus

E coli becomes competent?

when treated with CaCl2 and heat, membrane permeability

electroporation

subject cells to voltage

DNA binding protein

is on host cell

RecA

helps incorporate DNA strand into the chromosome

transduction

bacteriophage transfers DNA from one cell to another naturally

generalized transduction

phage contains only bacterial genes

specialized transduction

small protion of bacterial DNA integrated into viral genome

Conjugation

involves cell to cell contact, plasmids, copies transferred to new cell, donor cell, recipient cell, mainly gram -, few gram +

plasmids

small circular pieces of DNA

pilus

donor cell makes contact with recipent cell, pilus contracts

F+

donor cell, has pilus

F-

lacks pilus, recipient, after conjugation is F+

rolling circle replication

DNA replication continuous synthesis of a new strand as the original strand is unwound. plasmids and some bacteriophage DNA replication

plasmid functions

antibiotic resistance, virulence with attachment and toxins, metabolize additional substrates, facilitates conjugation, recombination, vectors in genetic engineering

innate immunity

non-specific defense response, bodys defenses against an array of pathogens, not specific, doesnt rely on previous exposure, barrier to invasion and some leukocytes

adaptive immunity

specific defense response, acquired ability to recognize and destroy specific pathogens, depends on previous exposure to pathogen, memory, antibodies, other leukocytes

barriers to invasion

physical and chemical: skin(keratin,sweat) tears(salt, rinsing) respiratory tract(mucous membrane, cilia) digestive tract(gastric juices, HCL, microbiota) urogenital

granulocytes

granules in cytoplasm, stain red/blue

neutrophils

lobed nucleus, phaocytic, active in early infection, circulationg, short lived, 60-70%

basophils

stain with basic dyes, blue granules, not phagocytic, histamines, inflammation, allergies, 0.5-1%

eosinophils

stain with acidic dyes, red granules, phagocytosis, release toxins agains worm infections, 2-4%

agranulocytes

lack granules

monocytes

develop into macrophages during infection, phagocytic, occur later in infection for years, 3-8%, fixed/circulation, harbor germs like TB, leprosy, herpes

dendritic cells

phagocytic and antigen presenting, fixed in mucous membranes, lymph nodes, spleen, epithelial, 0.2%

monocytes and dendritic..?

antigen presenting cells (APC) present antigens to lymphocytes, initiate immune response

lymphocytes

20-25%, antibody production

phagocytosis

ingesting & digesting foreign particulates

inflammation response

beneficial systematic inflammation life threatening like Spanish flu

fever

beneficial, hypothalamus, prostaglandins, increase temp, pyrogen-lipid A portion of lipopolysaccharide(LPS)

complement system

complements, assists, the bodys defenses, 30 glycoproteins incolved, serum, c1,c2,… interacct with one another cascading stimulated by immune system(antibodies) or directly by bacteria, classical pathway

cytolysis

membrane attack complex(MAC)

promote phagocytosis

C3b binds to surface of invading microbes, upsonization(enhances phagocytosis)

triggers histamine release

C3a, C5a attracts

specific defense response

humoral immune response, antibodies produced by B lymphocytes, act against extracellular pathogens

cell mediated immune response

elimination of antigens by T lymphocytes, doesn’t secrete antibodies, act against cells already infected

four properties of adaptive immunity?

1. specificity

2. diversity: potentially produce 10^7 different antibodies

3. memory: re-exposure to pathogen quick response

4. tolerance(discrimination): recognition of self vs nonself, self tolerance

antigen

immunogen, substance that causes antibody production in a host, found on living cells, viruses, large molecules, proteins, polysaccharides

antigen determinants/epitopes on surface

bind antibody or t cell receptor

antibody

produced by B lymphocytes in response to an antigen, glycoprotein, Y shaped

variable region

varies in a a sequences, antigen binding site (red, top)

constant region

consistent a a sequence (blue, bottom)

immunoglobulins

Ig

IgG

70-80%, most abundant, bind to antigen, cross placenta, trigger complement system, enhance phagocytosis(opsonization)

IgM

6-10%, pentamer, first to respond to antigen, found on rbcs surface, ABO blood groupnig

IgA

10-20%, dimer, external secretions, mucous, aliva, tears, breast milk

IgE

0.0003%, bound to mast cells and basophils, allergic response

IgD

0.2-0.3%, unsure of function, bind to B cells

B cells

lymphocyte that matures in lymph tissues or bone marrow, 20-30% of circulating, lymph tissues, spleen, tonsils, adenoids, have IgG and IgM antibodies,

plasma cells

secrete antibodies, short lived

memory cells

long lived, give lasting protection

T cells

lymphocyte that matures in thymus gland, 70-80%, fixed, lymph nodes, spleen, lack antibodies on surface, several types

Toll cell receptors

(TCR) proteins on cell surface of t-cells, receiver epitope

Major histocompatibility complex

MHC, antigens on body cells that identify self bind antigens

Class 2 MHC

b cells, macrophages, dendritic cells

antigen presenting cells

(APC) phagocytized pathogens involved in tissue transplant, donor and receiver need to match

antibody production

b cells first process antigens, have MHC sekf antigens, mhc2 involved

antibodies bind to antigen results in

1. fix complement

2. enhance phagocytosis(opsonization)

3. binds directly with toxins

4. prevent binding of viruses to cells

primary immune response

initial exposure to antigen, mostly IgM antibodies, have the disease, vaccine, first exposure to allergen

secondary immune response

re-exposure to antigen, dramatic increase in titer, IgG

phycology

the study of algae.