Biology Unit 6 - Gene Expression and Regulation

What are the nitrogenous pairs?

Adenine-Thymine/Uracil and Cytosine-Guanine

How is DNA and RNA different from their sugars?

DNA: deoxyribose, H atom

RNA: ribose, hydroxyl (-OH) group

Whats the difference between a purine and pyrimidine?

Purines: larger, double ring structure

Pyrimidines: smaller, single ring structure

Which of the nitrogenous bases are considered purines?

guanine, adenine

Which of the nitrogenous bases are considered pyrimidines?

cytosine, thymine, uracil

Whats a genome?

the complete set of an organism's genetic instructions, essentially its entire DNA

what are the characteristics of a prokaryotic genome?

circular chromosomes, plasmids found in the cytosol, small by comparison to the eukaryotic genome)

what are the characteristics of a eukaryotic genome?

linear chromosomes, found in the nucleus, large by comparison to the prokaryotic genome.

what is chargaffs rule for double stranded DNA?

1:1 ratio of purines to pyrimidines (A=T, C=G)

what happens during denaturation in PCR?

the double-stranded DNA template is heated to a high temperature, breaks the hydrogen bonds between complementary bases, and separates the DNA into two single strands.

what happens in annealing during PCR?

the temperature is lowered to allow primers to bind to their complimentary sequences

what happens in extension during PCR?

DNA polymerase synthesizes new strands (5’- 3’ direction)

what's the difference between a pipette and a micropipette?

pipette: transfer milliliters of water

micropipettes: transfer microliters of water

what is a parental and daughter DNA molecule?

parental: original DNA molecule

daughter: two new replicated DNA strands

what is transcription?

process by which RNA is synthesized from DNA

what is translation?

process in which a protein is synthesized from RNA

what is gene expression?

the process by which a gene is transcribed and translated

what is gene regulation?

processes that control whether gene expression occurs in a given time, in a given cell, or at what level

what are housekeeping genes?

expressed almost all the time by almost all cells

what is the central dogma order?

DNA, RNA, and protein

what are the characteristics of eukaryotes during transcription and translation?

• have a nucleus

• transcription occurs in the nucleus

• translation occurs in the cytoplasm

• processes are separated in space and time

• allows greater regulation of gene expression

what are the characteristics of prokaryotes during transcription and translation?

• no nucleus

• transcription and translation both occur in the cytoplasm

• occur at the same time and place

• less ability to regulate each step separately

what is the difference between prokaryotic and eukaryotic chromosomes?

prokaryotic chromosomes: single, circular DNA in the cytoplasm, and lacking histones

eukaryotic: multiple, linear DNA structures within the nucleus, tightly wrapped around histone proteins for organization

what is a nucleosome?

a section of DNA that is wrapped around a core of proteins

what is gel electrophoresis?

technique used to separate DNA and RNA based on size, and proteins based on size and charge

why is DNA negatively charged?

DNA has ionized phosphate groups along its backbone

what is the replication fork? What does DNA synthesis create?

the site where the parental DNA strands separate as the DNA complex unwinds, gives rise to 2 daughter DNA molecules

what is semi conservative replication?

DNA double helix unwinds and each strand serves as a template for building a new, complementary strand (both identical)

what are the enzymes (and protein) involved in DNA replication?

helicase, single strand binding protein, topoisomerase, DNA polymerase, primer, and DNA ligase

what is the function of helicase?

separates the strands of the parental double helix by breaking hydrogen bonds holding the base pairs together

what is the function of single strand binding protein?

binds to the single stranded regions to prevent the parental strands from coming back together

what is the function of topoisomerase?

manage DNA tangles upstream by cutting and resealing DNA strands to relieve supercoiling and prevent knots

what is the function of DNA polymerase?

carries out DNA replication

what is the function of a primer?

a short strand of DNA/RNA, used as a primer for DNA synthesis

what is the function of DNA ligase?

an enzyme that joins two DNA fragments together

what's the difference between a leading strand and lagging strand?

leading strand: one daughter strand is synthesized continuously (5’ - 3’)

lagging strand: other daughter strand is synthesized discontinuously (3’ - 5’)

what is the proofreading function in DNA polymerase?

DNA polymerase can immediately correct its own errors by excising and replacing a mismatched base

what is the polymerase chain reaction (PCR)?

technique that allows a targeted region of DNA molecule to be replicated many times

what are the 4 components of PCR?

DNA, DNA polymerase, all four nucleotides with different bases, and two primers

what are the 3 steps of PCR?

denaturation, annealing, and extension

what are PCR tests used for?

diagnostic of infectious diseases, genetic testing

What does DNA synthesis require?

a free 3' hydroxyl (-OH) group to add new nucleotides

What is a chain terminator?

inclusion of the ddNTPs to stop DNA strand elongation

what are restriction enzymes?

bacterial proteins that cut DNA at specific recognition sequences (restriction sites)

What is the first purpose of cutting DNA?

allows whole genomes to be broken into smaller pieces for further analysis

What is the second purpose of cutting DNA?

determines whether specific sequences are present in a segment of DNA

What is the third purpose of cutting DNA?

allows pieces from the same or different organisms to be brought together in recombinant DNA technology

what is recombinant DNA technology?

method for combining DNA from different sources to create new genetic combinations

What 4 things are required in the recombinant DNA process?

donor DNA, vector DNA, restriction enzymes, DNA ligase

What are three examples of where recombinant DNA technology is used?

GMOs, DNA editing, CRISPR

The end goal of DNA Sequencing is

to determine the nucleotide sequence in a DNA sample

what is a transgenic organism?

organisms whose DNA has been altered by adding one or more genes from a different species using biotechnology, resulting in a new trait not naturally occurring in that organism

Which of the following is a correct description of DNA transformation?

The uptake of foreign DNA by a cell that results in a genetic change

genetic testing can be used to determine:

when someone developed a genetic disease, whether there are mutations in someones DNA, what caused a mutation in the DNA

true or false: when a somatic cell with mutations divides, the daughter cells will also carry the mutations

true

true or false: mutations that occur in non-reproductive cells (somatic cells) are passed down to offspring

false