Biological Science I (BSC 2010) Exam Review

A collection of vocabulary flashcards covering key terms and definitions from the Biological Science I lecture material.

DNA replication

The process by which a cell makes a copy of its DNA, ensuring each daughter cell receives an identical set.

Avery, McCarty, and MacLeod

Researchers who showed that DNA is the transforming substance responsible for genetic inheritance.

Hershey and Chase experiment

Demonstrated that DNA is the genetic material by using bacteriophages and radioactive labeling.

Chargaff's rules

In any species, the amount of adenine (A) equals thymine (T), and the amount of guanine (G) equals cytosine (C).

Transformation

A change in genotype and phenotype caused by the assimilation of external DNA.

Semiconservative replication

The model of DNA replication where each daughter molecule consists of one old and one new strand.

DNA polymerase

An enzyme that synthesizes new DNA strands by adding nucleotides during DNA replication.

Okazaki fragments

Short segments of DNA synthesized discontinuously on the lagging strand during DNA replication.

Telomeres

Repeated nucleotide sequences at the ends of eukaryotic chromosomes that protect them from degradation.

Transcription

The process of synthesizing RNA from a DNA template, where RNA polymerase binds to the promoter.

Translation

The process of synthesizing a polypeptide from mRNA, occurring at the ribosome with the help of tRNA.

Operon

A cluster of functionally related genes regulated together, common in prokaryotic gene expression.

Repressor

A protein that inhibits gene transcription by binding to the operator of an operon.

Endocrine signaling

A form of long-distance signaling where hormones are released into the bloodstream to target distant cells.

Alternative RNA splicing

A process that allows a single gene to produce multiple proteins by including or excluding certain segments during RNA processing.

Point mutation

A change in a single nucleotide pair in DNA, which can lead to changes in protein structure and function.

Signal transduction

The process by which a cell converts an extracellular signal into a functional response.

Quorum sensing

A process where bacteria communicate and coordinate behavior based on population density.

what showed demonstrations of bacterial transformation

The Griffith heat treated transforming factor

who showed that the transforming factor is separable

the Avery-MacLeod-McCarty experiment

who showed that the Transforming factor is DNA

Hershey and Chase using radioactive PROTEIN AND DNA IN BAVTERIA PHAGE

who showed the ratios of DNA within and between species

Chargaff's rules, formulated by Erwin Chargaff. These rules state that the amount of adenine (A) equals thymine (T) and the amount of cytosine (C) equals guanine (G) in DNA.

who built models of dna structure

watson and Crick

who used X-ray crystallographic images of DNA that allowed watson and crick to propose their model

Rosalind Franklin

who proved the Semi-conservative replication

was demonstrated by Matthew Meselson and Franklin Stahl through their experiment using nitrogen isotopes. heavy and light .

what polymerase removes primers 5’ and fills in nucoltides from 3’ end

DNA polymerase I

important in okazaki fragments

dna polymerase III

is the primary enzyme involved in DNA replication, responsible for adding nucleotides to the growing DNA strand in the 5' to 3' direction.

dna polymerase II

DNA repair especially in SOS response and also involved in the replication of damaged DNA.

DNA polymerase I

An enzyme that removes RNA primers during DNA replication and replaces them with DNA nucleotides.

single strand binding protein

A protein that stabilizes single-stranded DNA during replication, preventing it from re-annealing or forming secondary structures.

Topoisomerase

An enzyme that alleviates supercoiling and torsional strain in DNA during replication and transcription.

where is mrna synthesized

mRNA is synthesized in the nucleus during the process of transcription.

the poly a tail is located on what end

the 3’ end

transcription factors mediate the binding of

RNA polymerase to the promoter region of a gene, initiating transcription.

a promoter called a __ is crucial in forming the initiation complex in eukaryotes

TATA box

Enzymes in the eukaryotic nucleus modify pre-mRNA where in the cell

nucleus

during modification the 5’ end receives a

modified nucleotide 5’ cap

during modification the 3’ end gets

gets a poly-A tail

the lac operon is an ______operon

inducible

the ______ operon

repressible operon

When tryptophan is present, the operon is

it binds to the trp repressor protein, which turns the

operon off

iii. The repressor is active only in the presence of its corepressor tryptophan; thus the trp operon is turned off (repressed) if tryptophan levels are high

for the lac operon to be on do you need high or low cAMP

high

when glucose levels are low, cAMP levels are

high. activating CAP. helps the polymerase transcribe lac z

When glucose levels are high, cAMP levels are

CAP detaches from the lac operon, and transcription returns to a

normal rate

The addition of methyl groups (methylation) can

condense chromatin

DNA methylation can cause long-term inactivation of genes in cellular differentiation

the addition of phosphate groups (phosphorylation) next to a methylated amino acid can

loosen chromatin

promoting the initiation of

transcription

Eukaryotic mRNA is more long lived than prokaryotic mRNA

miRNAs

hese can degrade mRNA or block its translation

f.

siRNAs

play a role in heterochromatin formation and can block large regions of the

chromosome