Intro to Bio 2-Chapter 12

lagging strand

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork.

DNA ligase

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.

In the 1940s, scientists had concluded that the genetic material was most likely either _____ or _____

DNA or protein

Transfer RNA (tRNA)

An RNA molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and recognizing the appropriate codons in the mRNA

Which of the following were direct contributions of the work of James Watson and Francis Crick?

Deduced the double helix shape of deoxyribonucleic acid Determined that nucleotides were paired inside the double helix Determined that sugars and phosphates formed backbones in the DNA

gene expressions

genes are expressed when the polypeptides are modified into their structure to become functioning proteins

process of translation

initiation, elongation, termination

translation

the mRNA transcript is read by a ribosome and converted into the sequence of amino acids in a polypeptide

The process of synthesizing an RNA strand from a DNA template strand is called

transcription

What comes first, transcription or translation?

transcription

What is the source of particular sequences of tRNA, mRNA, and rRNA?

transcription from DNA

For a protein, gene expression requires _______in the nucleus and ______at the ribosome to take place.

transcription; translation

gene expression

transfer of information from the genetic material (DNA) to RNA and onto a protein. transcription and translation

The process which uses mRNA, tRNA, and ribosomes to synthesize proteins is called

translation

wat does replication result in?

two double helix molecules, each having 1 parent & 1 new strand

ribosomal RNA

type of RNA that makes up the major part of ribosomes

proetomics

understanding the structure of proteins and how they functions in metabolic pathways

Error rate in eukaryotes

varies depending on the size of the genome

introns

Noncoding segments of nucleic acid that lie between coding sequences. removed by splicesomes

Which of the following are components of a nucleotide?

Phosphate 5-carbon sugar Nitrogen-containing base

does RNA have a double helix?

no

the ribosome 3D structure

Two subunits made of ribosomal RNA and proteins; can be free in cytosol or bound to ER

characteristics of the genetic code

Universal, redundant, specific

what is each parent DNA for new DNA?

a template

nitrogenous bases of RNA

adenine, guanine, cytosine, uracil

many RNA transcripts on one DNA molecule....

allows cell to better respond to chaining environmental conditions

Incorporating new nucleotides into DNA can provide it with the ability to code for a greater number of

amino acids

what does the end of the molecule have in translation?

an anticodon-group of 3 bases

what is a replication bubble

an unwound and open region of a DNA helix where DNA replication occurs

what are the strands of DNA?

antiparallel

rRNA strands are transcribed from a template strand of DNA found in the _______.

nucleolus

what is transformation of bacteria?

bacterial cells absorb and incorporate pieces of DNA from environment (usually dead bact. cells).

How are nucleotides joined together?

by linking the 5' phosphate of one nucleotide to a free hydroxy located at the 3' position on the sugar of the preceding nucleotide

In prokaryotes, replication can occur in two directions at once because the DNA molecule is

circular

Prokaryotic cells have ______ DNA and their DNA replications proceeds in a ______ direction.

circular; 5' to 3'

the genetic code

collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis

what is DNA?

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

The building blocks of DNA are

nucleotides

joining in replication

nucleotides are connected/bonded to each other (sugar-phosphate covalent bond)

complementary base pairing in replication

nucleotides move into position and pair with those on the template

What did Watson and Crick discover?

double helix structure of DNA

The coding portions of a gene that are joined during mRNA processing are called

exons

saying for introns and exons

exons are expressed and introns are in the way

what is synthorax

expanded genetic alphabet creating two new world of bases called X & Y

exons

expressed sequence of DNA; codes for a protein

The production and usage of a gene's product is called gene____

expression

Thymine and cytosine are nitrogen-containing bases called

pyrimidine

what is RNA

ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins,

R strain bateria

rough appearance, mice did not die

replication is ______

semiconservative

How did Rosalind Franklin contribute to determining the structure of DNA?

she used x-ray diffraction patterns to show the DNA double helix

dna primase

short complementary sequences of RNA (primers) are laid down to initiate synthesis

polyribosome

string of ribosomes simultaneously translating regions of the same mRNA strand during protein synthesis

what does mRNA codon determine

the amino acid

what does tRNA transport?

the correct amino acid to the ribosome

what are the steps in replication?

1. Unwinding 2.Complementary base pair 3. Joining

process of transciption

1. initiation- RNA polymerase bonds to the promote region of the gene= DNA unwinds 2.elongation- RNA polymerase moves along the DNA template and synthesizes RNA 3. termination-RNA polymerase encounters the terminator sequence

Error rate in prokaryotes

1/100million pairs

what is the structure of DNA

-composed of polynucleotides -- have a phosphate group, deoxyribose sugar and a nitrogen containing bases (adenine, thymine, cytosine and guanine) -Has a doubled helix that is formed by hydrogen bonds between polynucleotides -Densely compacted into chromosomes to fit into nucleus

prokaryote replication

1 circular chromosome, in the nucleoid region of prokaryote, 1 origin, in 2 directions (leading & lagging strands) very fast

replication fork

A Y-shaped region on a replicating DNA molecule where new strands are growing.

the codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

The two purines bases in DNA are:

Adenine and Guanine

Which of the following are similarities between prokaryotic and eukaryotic DNA replication?

Both result in 2 copies from one parent molecule Both involve DNA polymerase Both are semiconservative Both happen from the 5' to 3' direction

What does guanine pair with?

Cytosine

Central Dogma of Molecular Biology

DNA -> RNA->AA sequence ->specific polypeptide -> Protein

dna polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

messenger RNA

RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

Transcription

RNA molecules are produced by copying part of the nucleotide sequence of DNA into a complementary sequence in RNA

Unwinding in replication

Requires helicase activity. The dsDNA is unwound producing a replication bubble made of open ssDNA.

when does replication occur in the cell cycle?

S phase of interphase

S strain bacteria

Strain of Streptococcus pneumoniae that causes pneumonia (it would be SO BAD to be infected by this one)

leading strand

The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction.

What does adenine pair with in DNA?

Thymine