Biomed test 1

genome

the complete set of genes present in a cell/organism

Human Genome Project

a project preformed with the goal of determining the base pairs that makeup DNA

Helicase:

unwinds DNA strands

Topoisomerase

helps prevent strain on the strand

Primase

intiaties replication

DNA polymerase

keeps DNA strands seperate

Translation

mRNA is decoded to bulid a protein tha contains a specific series of amino acids

Single gene disorders

are caused by changes/mutations that occur in the DNA sequences

are inherited in recognizable patterns such as autosomal dominant, autosomal recessive, and sex linked

Multifactorial disorder

are caused by environmental factors + multiple genes

How are Single gene disorders discovered?

Electrophoresis

how are multifactorial disorders found out?

Karyotype and Electrophoresis

Chromosomal Abnormalitiy

problems arise when there are missing/extra copies of genes or breaks

Mitochondrial Disorder

caused by mutations in non-chromosomal DNA of mitochondria

• usually passed from mother to child

Incomplete dominance

2 dominant alleles are present but both blend to create 3rd phenotype (Grey from black and white)

Codominance

2 dominant alleles in which both show up in the phenotype (think emma)

genotype

genetic makeup of individual organism

phenotype

set of observable characteristics of an individual organism arising from the genotype and enviornment

Single Nucleotide Polymorphisms

a type of genetic variation where the genome sequence of 2 individuals differ at a single nucleotide

genetic testing

the use of methods to determine if someone has a genetic disorder will develop one, or is a carrier

PTC

a chemical which releases a bitter taste

TAS2R38

the gene for the PTC taste receptor

Restriction Fragment Length polymorphisms (RFLPS)

a technique that exploits variations in homologous DNA sequences

PCR

a technique that involves copying short peices of DNA and then making millions of copies in a short period of time

Restrictive enzymes

enzymes that cut DNA at specific sequences

what kind of charge does DNA naturally have?

negative

Chronic Virus sampling

a technique for diagnosing genetic and congenital defects in a fetus by removing and analyzing a sample of the fetal position of the placenta

Amniocentesis

a technique for determine genetic abnormalities in a fetus by the presence of certain chemicals or defective fetal cells in amniotic fluid, obtained by aspiration from a needle inserted into the uterus.

How long is the human genome?

3 billion base pairs

How many cycles does PCR usually run?

30 cycles

Denaturation

heat is applied to to break the bonds between bases on opposing strands. double stranded DNA is split into single-stranded DNA exposing the bases so they can be copied. Typically at 90-98ºC

annealing

As the PCR temperature is lowered, short pieces of DNA, called primers, bind to specific sequences within the genome targeting this region to be copied. annealing temperature is specific to the primers used in your reaction typically at 45-65ºC

extension

at around 70ºC the polymerase gets to work and starts adding nucleotides to the 3’ end of the annealing primers, copying the complementary strands. Typical settings for 72ºC

Allele

One or two or more distinct forms of a gene located at hte same position on homologous chromosomes

Buffer

a salt added to aqueous solution that helps maintain a consistent pH. are essential in PCR because the DNA polymerase’s function is sensitive to pH changes

Cycle

referes to one round of denaturation, annealing, and extension steps of the PCR reaction. the quantity needed for a particular reaction will depend on how much DNA you are starting out with and how much DNA you are trying to produce

dNTPS

nucleotides, the molecular building blocks of DNA

Enzyme

a biological catalyst that speeds up a chemical reaction without changing the products or being consumed by the reaction. most are proteins and control a wide range of reactions in cells, from copying DNA to extracting energy from food

Final Extension

in some protocols, an additional extension step in used. this ensures that the polymerase can add the final base pairs onto the end of the strands, which is necessary in some applications.

Initial Denaturation

when copying a piece of genomic DNA, this step is often used to make sure the long strands of DNA are fully separated and freed from bound proteins before thermal cycling begins. Typical settings are 90-96ºC

Monomer

a molecule that can be bonded with other similar molecules to form a polymer

polymer

a molecule that consists of many similar units bonded together

Primers

short peices of DNA with sequences complementary to the sequences flanking the region to be copied. are designed specificially for every PCR reaction taking many variables into account, including length, nucleotdie content, and structural features

Recognition Site

the specific DNA sequence that a restriction enzyme recognizes and binds to

Template

DNA containing the sequence that will be copied in a PCR reaction. can be a short fragment or a whole genome

Thermal Cycler

Also called a PCR machine is an instrument that automatically changes the temperature the PCR reaction according to a program set up by the user.