hmwrk 11 exam review

Primer

Short nucleic acid sequence that initiates transcription.

Promoter

DNA sequence where transcription begins, binding RNA polymerase.

Origin

Site where DNA replication starts, not transcription.

Start codon

AUG; signals start of translation process.

5' cap

Modified guanine nucleotide protecting mRNA from degradation.

3' poly-A tail

String of adenine nucleotides aiding mRNA stability and export.

Exon-encoded RNA

RNA segments that code for proteins in mature mRNA.

Intron-encoded RNA

Non-coding RNA segments removed during mRNA processing.

Initiation complex

Assembly of mRNA, ribosomal subunits, and tRNA for translation.

Central dogma

Flow of genetic information: DNA to RNA to protein.

N-terminus

Start of a polypeptide chain, always has Methionine.

Missense mutation

Change in DNA sequence resulting in different amino acid.

Nonsense mutation

Mutation creating a premature stop codon in protein.

Silent mutation

Change in DNA sequence with no effect on protein.

Deletion mutation

Loss of nucleotides in DNA sequence affecting protein.

σ subunit

Part of RNA polymerase involved in transcription initiation.

Ribosome binding

Process facilitated by 5' cap and poly-A tail.

mRNA degradation

Process prevented by 5' cap and poly-A tail.

Translation

Process where ribosomes synthesize proteins from mRNA.

Why is primase required for DNA replication ?

DNA polymerase requires a free 3 ' - OH group onto which to add DNA nucleotides Primase makes a short RNA primer to provide a 3 ' - OH group for DNA polymerase to attach the incoming DNA nucleotide

The process of making an RNA copy of a gene is called

Transcription

A cell's remains constant whereas its phenotype changes in response to environmental influences

Genotype

Can two observably different cells have the same genotype ? Explain your answer

same have Yes , cells that have the same genotype can be phenotypically different . They may look different because of growth under different environmental conditions which led to the expression of different subsets of genes in each .

Below is a DNA sequence . Envision that this is a section of a DNA molecule that has separated in preparation for replication , so you are only seeing one DNA strand Construct the complementary DNA sequence in both the 5 ' - 3 and 3 ' - 5 ' directions DNA sequence 3 ' - TACTGACTGACGATC - 5 '

5 ' - ATGACTGACTGCTAG - 3 ' and 3 ' - GATCGTCAGTCAGTA - 5 '