micro unit 2 red

define genetics

the study of heredity

define trait

a genetically determined characteristic

define genome

the complete set of genes or genetic material present in a cell or organism

define gene

segment of DNA that codes for a protein

the significance of microbial genetics to understanding howmicrobes function and cause infection

the ability of a microbe to cause disease is based on the set of structures they have and functions their cells can perfrom

basic structure of dna

double helix - two single chains that spiral around an imaginary axis

define backbone of DNA

portion of helix that provides outside support

define base

A,C,T,G

base pair

A pair of complementary nitrogenous bases in a DNA molecule

double helix

Shape of DNA

strand of dna

Many nucleotides connected together in a single line

nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

three parts of nucleotide

sugar nitrogenous base phosphate group

what holds a base pair together

hydrogen bonds

rules of base pairing for DNA

bases must always pair together in a DNA molecule the same way every time

complementarity in DNA

property of DNA

genetic sequence

determining the order of the four chemical building blocks - called "bases" - that make up the DNA molecule.

Know the importance of proteins to cells and why cells must turn the instructions in their genes into proteins.

proteins performs most of the work of living cells

• provides the cell with a potential control point for self-regulating its functions by adjusting the amount and type of proteins it manufactures.

rules of central dogma

genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.

transcription

synthesis of an RNA molecule from a DNA template

translation

Process by which mRNA is decoded and a protein is produced

what happens during the process of transcription.

mRNA molecules are made from a DNA template

coding strand

the strand of DNA that is not used for transcription and is identical in sequence to mRNA, except it contains uracil instead of thymine

template strand

The DNA strand that provides the template for ordering the sequence of nucleotides in an mRNA transcript.

rna polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

three major differences between dna and rna

RNA: contains ribose, uracil, single stranded DNA: contains deoxyribose, thymine, double stranded

base pairing rules in RNA

A, U, C, G

AGCCTAACG give complementary base pair of DNA

TCGGATTGC

AGGTA give RNA sequence

UCCAU

Know where transcription and translation happen in prokaryotic and eukaryotic cells

prokaryote: cytoplasm eukaryote: nucleus

know the basic structure of a protein

long chains of amino acids

be able to define the term protein sequence

to read the order of amino acids in a protein

Know what a codon is

codon: genetic sequence of RNA molecule organized into three letter words

how are codons translated into an amino acid sequence with the genetic code

start from the center of the chart and follow the RNA codons until you have three nucleotide bases

Know the significance of the MET and STOP codons in translation

MET: start Stop: stop

Know the basics of how the process of translation occurs and how tRNA is used in that process

t stands for transfer, it will form base pairs with the mRNA which allows it to carry the correct amino acid into ribosome

Know the two reasons discussed in class that understanding microbial genetics is important for medical microbiology

1. many antimicrobial drugs we use to stop growth of microbes will try to stop transcription and translation from happening in microbial cells

2. genetic mutations and variants in microbes will change the function of their proteins

Know what a mutation is

permanent changes to the genetic sequences in a genome

how a mutation can result in changes to protein sequences and protein function

mutations change sequence of mRNA which will change the sequence of protein being made

Know what protein folding is, why each protein folds into a unique shape, and why that shape is important for its function

what: when a protein folds into 3D shape why unique: because every protein has unique sequence of amino acids why is it important: it makes it fully functional and determines what molecules are able to bind to it

what are the three types of mutations

insertion, deletion, substitution

insertion mutation

the addition of one or more nucleotide base pairs into a DNA sequence

deletion mutation

a mutation in which one or more pairs of nucleotides are removed from a gene

substitution mutation

Mutation in which a single base is replaced, potentially altering the gene product.

silent mutation effect

no effect

missense mutation effect

changes one amino acid to another in the protein's seqeunce

nonsense mutation effect

changes one amino acid to STOP codon

frameshift mutation effect

mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide

Be able to explain why frameshift mutations often cause extreme changes in protein

insertions and deletions often change the entire reading of the codon (the dog ran to far)

Know the two ways that mutation can happen

spontaneous and induced

spontaneous mutation

occurs because of errors in the processes that copy DNA molecules or repair damage to them

induced mutations

caused by presence of intense radiation or chemicals that can damage DNA structure

Know the process of DNA replication and the function of the three enzymes we discussed that participate in the process (topoisomerase, gyrase, DNA polymerase)

replicate through cell division: a protein called gyrase will seperates the two strands of DNA and then topoisomerase unwinds the two DNA strands of a chromosome, actual copying done by DNA polymerase

Know the definition of mutation rate

frequency with which cells make errors

know how mutation rates compare between eukaryotic cells, bacterial cells, and viruses

viruses are very prone to error

• eukaryotes mutate more than prokaryotes

Know the definition of asexual reproduction

the production of genetically identical offspring by a single cell

the general stages of asexual reproduction

dna rep, cell division, and cell separation

which microbes are capable of asexual reproduction

prokaryotes (bacteria and archaea) certain protozoans

similarities and differences between binary fission and mitosis

similar: dna rep, cell division, cell separation differences: is binary fission the cell wall splits external structures in half

Be able to explain how sexual reproduction occurs in microbes and its outcome

the production of genetically distinct offspring by combining 2 haploid cells through two series of meiosis cell divison

heploid

one set of chromosomes

diploid

2 sets of chromosomes

gamete

sex cell

meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

Know the basics of the process of meiosis and the types of cells it produces

gametes four haploid daughter cells

Know which types of reproduction each major group of microbes can perform. bacteria, fungi, protozoa, helminths

bacteria: asexual some fungi/protozoa are only asexual and some are asexual and sexual helminths: sexual reproduction

what reproductive strategy is used in the mosquito stage of malaria

sexual reproductive

Know when organisms prefer to use asexual

• active growths of infection

• faster

• less energy to perform

• no requirement for finding mate cell to combine with

Know when organisms prefer to use sexual

-preferred when rapid growth of parasite becomes poor

• increase genetic diversity and likelihood the offspring will survive in bad conditions

• dormant and resistant stages

• resets complex life cycle

what is growth rate in microbiology

rate or speed at which number of organisms in population increases

how does growth rate impact microbes ability to evolve through genetic change/cause infection

they must grow fast enough to stay ahead of the immune system's ability to identify and kill them

Know why asexual reproduction strategies are preferred during infection

allows production to be faster and at lower energy cost

Know why asexual reproduction produces exponential growth of microbes and howthat is defined mathematically

a single parent cell produces two offspring cells each time it reproduces P = P02^N

generation time

time it takes for each generation of doubling

ideal growth conditions

chemical and physical needs of a cell that maximize their growth rate

which growth conditions can impact growth rates (5)

1. availability of nutrients, vitamins, and biological molecules

2. temp

3. ph

4. salt concentrations

5. oxygen availability

what is a range tolerance

range of environmental conditions that can be tolerable by a species for the species revival

minimum value

The smallest value in a set of data.

maximum value

The largest value in a set of data.

optimum value

The value at which the survival rate of the species is highest

generalists

species with broad niches

specialists

species that have narrow niches

fastidious

specific complex nutrients or other growth factors

mesophiles

moderate temperature loving microbes

• human pathogens

Psychrophiles

cold-loving microbes

• listeria pathogens which cause contamination in food

thermophiles

hot shower temp

• shallow water like parasites

what are the two groups that human pathogens fall into for optimum pH

neutrophiles and acidophiles

neutrophiles

grow best in a narrow range around neutral pH

acidophiles

grow in acidic environments

what are the two groups that humans fall into for optimums of salt

non halophiles and halotolerant

non halophiles

unable to handle high salt concentrations

halotolerant

grow best in high salt concentration

what does oxygen based metabolism create

toxic oxygen byproducts that damage cells

obligate aerobes

require oxygen

what does it mean if oxygen is actively toxic

lacks antioxidants for some cells need little to none oxygen

facultative anaerobes

can live with or without oxygen

aerotolerant anaerobes

do not utilize oxygen but can survive and grow in its presence

Know the functions that viruses can perform (slide 8/9) and those that they can't and why that means they must infect cells (slide 1)

viruses are built to:

• find their way into cytoplasm of living cells

• make as many copies of a virus as possible virsues cant:

• make ATP

• make protiens

• dont have polymerase to make RNA or replicate genome

Know the basic structure of a virus including the three major anatomical parts

1.genome - genetic sequences used to make viral proteins 2.capsid - surrounds and protects genome 3.envelope - outer covering of phospholipids

Know how the types of genomes available to viruses differ from the types of genome found in cells

single stranded and double stranded

• viral genomes are typically smaller