Biochemistry Of The Genome

Question 1

DeoxyriboNucleotide components

Answer 1

Nucleotides that compose DNA.
5 carbon sugar (ribose or deoxyribose)
Phosphate group
Nitrogenous base

Question 2

Nucleic Acids

Answer 2

Macromolecules composed of monomers called “nucleotides”, which are polymerized to form large strands.
Store the genetic info. Needed for building and controlling the cell

Question 3

Nitrogenous base pairs

Answer 3

Adenine, guanine, cytosine, thymine, and uracil.

Question 4

Purines

Answer 4

Adenine and guanine, they have a double ring structure with a 6 carbon ring fused to a 5 carbon ring

Question 5

Pyramidine

Answer 5

Cytosine and thymine, are smaller nitrogenous bases that have only a 6 carbon ring structure.

Question 6

Chargaff’s Rule

Answer 6

A=T and C=G. Complimentary base pairs.

Question 7

Why is the double helix of DNA described as antiparallel?

Answer 7

DNA is made up of 2 stands that are twisted around each other to form a right handed helix. The 2 strands are “antiparallel” such that the 3” end ( hydroxyl group) of one strand faces the 5” end ( phosphate group) of the other.

Question 8

How are nucleic acids formed?

Answer 8

Monomers are linked together by condensation reaction and a phosphodiester bond (covalent bond) forms between nucleotides.

The bond form between the 3” OH of one nucleotide and the 5”phosphate of a second.

Question 9

Transposons

Answer 9

Mobile segments of DNA that can move within the genome of an organism, regulates gene expression, protein expression, and virulence.

Question 10

Phosphodiester bonds

Answer 10

“Linkages” individual nucleoside triphosphates combine with each other by covalent bond (5-3) whereby the phosphate group attached to 5 carbon of sugar bonds to hydroxyl group of 3 carbon of sugar of next nucleotide

Question 11

Sugar phosphate backbone

Answer 11

Phosphodiester bonding between nucleotides. Alternating sugar phosphate structure composing the framework of a nucleic acid strand. During polymerization deoxynucelotide triphosphate (dNTP) are used.
Spacing of the backbone results in major and minor grooves where protein can bind to the DNA.
Proteins binding to DNA regulates DNA replication and transcription.

Question 12

Vertical Gene Transfer

Answer 12

Transmission of DNA info. From mother to daughter cell, occurs through DNA replication.

Question 13

RNA

Answer 13

Short and single stranded and made of ribonucleotides linked by phosphodiester bonds.
Components: ribose (Penrose sugar), one of four nitrogenous bases, and a phosphate group.
Forms a 3D structure by folding upon itself.

Question 14

3 types of RNA directly involved in protein synthesis

Answer 14

mRNA, rRNA, tRNA

Question 15

Messenger RNA

Answer 15

Serves as a photocopy of specific info needed at a particular point in time that serves as the instructions to make a protein. Carries message from DNA which controls cellular activities In cells.
It’s unstable and short lived.

Question 16

Ribosomal RNA

Answer 16

tRNA and rRNA are encoded in DNA then copied into long RNA molecules that are cut to release smaller fragments containing individual mature RNA species.
Stable.
Ensures proper alignment of mRNA tRNA and the ribosomes. Also has enzymatic activity (peptides transferase) and catalyzes formation of peptide bonds between 2 aligned amino acids during protein synthesis.
Composing 60% of ribosome mass.

Question 17

Transfer RNA

Answer 17

Smallest. Carries correct amino acid to site of protein synthesis in the ribosome. It’s the base pairing between tRNA and mRNA that allow for correct amino acid to be inserted in the polypeptide chain being synthesized. Any mutations here can result in global problems for the cell.
Contains amino acid binding site and mRNA binding site.

Question 18

Genome

Answer 18

All of an organisms genetic material

Question 19

Genes

Answer 19

Segments of DNA molecules. Individual genes contain instructional code necessary for synthesizing various proteins, enzymes, or stable rna molecules.

Question 20

Genotype

Answer 20

Full collection of genes that a cell contain within its genome. Can be turned on and off.

Genotype determined the phenotype.

Question 21

Phenotype

Answer 21

Observable characteristics.

Question 22

Constitutive genes

Answer 22

Genes that are always expressed. “House keeping genes” necessary for basic functions of the cell.

Question 23

Supercooling

Answer 23

Process by which DNA is twisted to fit inside the cell.

Question 24

Dna packaging

Answer 24

Dna binding proteins, histones, perform levels of dna wrapping and attachment to scaffolding proteins.

Question 25

Epigenetics

Answer 25

Influence of environmental factors on DNA packaging. Regulates gene expression without altering sequence of nucleotides. Maintained through rounds of cell division, therefore can be heritable.
Methylation of cytosine on DNA.

Question 26

Noncoding DNA

Answer 26

doesn’t encode proteins or stable RNA products. Commonly found in areas prior to the start of coding sequences of genes as well as intergenetic regions

Question 27

Extrachromosomal DNA

Answer 27

Additional molecules of DNA outside the chromosome that are also part of its genome.

Question 28

Horizontal gene transfer HGT

Answer 28

bacteria exchange plasmids with other bacteria

Question 29

Nucleic acid structure

Answer 29

Contains five carbons.
2” carbon Determines if the nucleotide makes up DNA or RNA.
(Deoxyribose for DNA lacks a hydroxyl group on the 2” carbon. Deoxy=missing oxygen)

Question 30

Pyrophosphate

Answer 30

Contributes energy to drive polymerization

Question 31

Hydrogen bonds of base pairs

Answer 31

T-A have 2 hydrogen bonds
C-G have 3 hydrogen bonds

Question 32

Denature

Answer 32

DNA strands with more g-c bonds require more energy to break apart (denature) than those with more a-t bonds.

Question 33

RNA In viruses

Answer 33

Are double stranded and specific for viruses (indicate viral infections).
Viruses that don’t have DNA will have RNA as their hereditary info.

Question 34

Karyotypes

Answer 34

The number and visual appearance of chromosomes in the nuclei of specific organisms.
Eukaryotic species have different karyotypes.