Genetics General

Front 1

Structure of DNA strand. What does each nucleotide monomer consists of?

Back 1

Nitrogenous base (T, A, C or G);
Sugar deoxyrebose;
Phosphate group.

Front 2

What does the 'backbone' of DNA strand consists of?

Back 2

The phosphate of the nucleotide is attached to the sugar of the next. The bases project from them.

Front 3

What directionality does the polynucleotide strand have?

Back 3

From 5' (with the phosphate group) end to 3' (with the -OH group) end.

Front 4

What does 5' and 3' refer to?

Back 4

It refer to the numbers assigned to the carbons in the sugar ring.

Front 5

What specific combinations are the nitrogenous bases of the double helix pared in?

Back 5

Adenine with Thymine; Guanine with Cytosine.

Front 6

What are purines?

Back 6

Adenine and Guanine are purines, nitrogenous bases with two organic rings.

Front 7

What are pyrimidines?

Back 7

Cytosine and Thymine are nitrogenous bases which have one organic ring.

Front 8

How many hydrogen bonds are there between G and C?

Back 8

Three.

Front 9

How many hydrogen bonds are there between A and T?

Back 9

Two.

Front 10

What form does bacterial chromosome has?

Back 10

Circular.

Front 11

What are DNA and RNA?

Back 11

DNA and RNA are nucleic acids, polymers made of subunits called nucleotides.

Front 12

Give an example of the biological molecular components common in a typical cell in a DNA pyrimidine nucleotide?

Back 12

Base (C or T), sugar deoxyribose, phosphate group.

Front 13

What is the difference between the sugars in DNA and RNA molecules?

Back 13

DNA contains the sugar deoxyribose, while RNA contains the sugar ribose. Ribose has one more oxygen atom than deoxyribose.

Front 14

Nucleotide

Back 14

The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Front 15

How do nucleotides differ?

Back 15

They differ in their nitrogenous bases. The nitrogenous bases guanine and adenine each have two linked rings of atoms. They are called purines. Cytosine, thymine, and uracil each have a single ring, and these three bases are called pyrimidines.

Front 16

What are the 1', 3' and 5' carbon atoms linked to in a nucleotide sugars?

Back 16

The 1' carbon is bonded to the nitrogenous base, the 3' carbon to the next nucleotide, and the 5' carbon to the phosphate group.

Front 17

Polynucleotide

Back 17

A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA.

Front 18

Covalent bond

Back 18

A type of strong chemical bond in which two atoms share one or more pairs of valence electrons.

Front 19

In which direction are polynucleotides assembled?

Back 19

In the 5' to 3' direction.

Front 20

How does the two DNA strands hold together?

Back 20

The two DNA chains, or strands, are held together by hydrogen bonds between the nitrogenous bases on opposite strands.

Front 21

Double helix

Back 21

The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape.

Front 22

Gene

Back 22

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses).

Front 23

The parental DNA

Back 23

The parental DNA is the original double-stranded DNA molecule. It is copied during DNA replication.

Front 24

Nucleosome

Back 24

The basic, bead-like unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a protein core composed of two copies of each of four types of histone.

Front 25

What does nucleosome consist of?

Back 25

Each nucleosome consists of a DNA segment wound around a protein core of eight histone molecules.

Front 26

Histone

Back 26

A small protein with a high proportion of positively charged amino acids that binds to the negatively charged DNA and plays a key role in its chromatin structure. Histones are involved in switching genes on and off.

Front 27

Autosome

Back 27

A chromosome that is not directly involved in determining sex; not a sex chromosome.

Front 28

Protein

Back 28

A three-dimensional biological polymer constructed from a set of 20 different monomers called amino acids.

Front 29

ATP

Back 29

(Adenosine triphosphate) An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.

Front 30

Genome

Back 30

All the genes, whether they are expressed or not.

Front 31

Transcriptome

Back 31

All the genes that are being transcribed - variable depending on cell type and stage of development.

Front 32

Proteome

Back 32

All the genes that are being translated - variable depending on cell type and stage of development.

Front 33

Metabolome

Back 33

Non-genetically determined - all the metabolites. Typically assayed in urine or blood by nuclear magnetic resonance. Like the transcriptome and the proteome, the metabolome is dynamic, changing from second to second.

Front 34

cDNA

Back 34

Complementary DNA (cDNA) is DNA synthesized from a mature mRNA template in a reaction catalyzed by the enzyme reverse transcriptase and the enzyme DNA polymerase. cDNA is often used to clone eukaryotic genes in prokaryotes. When scientists want to express a specific protein in a cell that does not normally express that protein, they will transfer the cDNA that codes for the protein to the recipient cell. cDNA is also produced by retroviruses which is integrated into its host to create a provirus.

Front 35

Gel electrophoresis

Back 35

The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.

Front 36

What is the basic working mechanism behind gel electrophoresis?

Back 36

Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), or protein molecules using an electric field applied to a gel matrix. It separates molecules according to their size. Molecules (of DNA, for example) will move towards the positive end of the gel, when the electrical current is run through the gel. Bigger (longer) molecules will move more slowly, because it will be more difficult for them to move through the gel. The number of bands on the gel indicates the number of different sized molecules loaded in the gel.

Front 37

Gel electrophoresis: If you want to compare the amount of particles in different bands appearing in the gel what feature should you look at?

Back 37

The thickness of the bands. Thicker it is - more molecules there are of a specific size.

Front 38

gel electrophoresis: What is a molecular weight standard?

Back 38

It is basically a test tube that contains a known sizes of DNA.