Nucleic Acids and Protein Synthesis Flashcards

Flashcards covering the structure of nucleic acids (DNA, RNA, ATP), the process of protein synthesis (transcription and translation), and various types of mutations.

Nucleic Acids

Important polymers made up of subunits called nucleotides that include DNA, RNA, and ATP; they function as the blueprints of life and energy carriers.

Nucleotide

The basic unit of nucleic acids consisting of three components: a pentose sugar, a phosphate group, and a nitrogen base.

James Watson, Francis Crick, and Rosalind Franklin

The scientists credited with the discovery of the DNA molecule structure; the Nobel Prize was awarded to Watson and Crick in 1962.

Purines

Double-ringed nitrogen bases, specifically Adenine (A) and Guanine (G).

Pyrimidines

Single-ringed nitrogen bases, which include Cytosine (C), Thymine (T) in DNA, and Uracil (U) in RNA.

Phosphodiester bond

A chemical bond formed when the phosphate group on the $5^{th}$ carbon of one nucleotide links to the $3^{rd}$ carbon of another nucleotide through dehydration synthesis (condensation).

Complementary Base Pairing (cbp) in DNA

The specific bonding where Adenine pairs with Thymine ($A=T$) via double hydrogen bonds, and Guanine pairs with Cytosine ($G \equiv C$) via triple hydrogen bonds.

Antiparallel

The structural arrangement of DNA where the two strands run in opposite directions, one from $5'$ to $3'$ and the other from $3'$ to $5'$.

RNA (Ribonucleic Acid)

A single-stranded nucleic acid containing a ribose sugar and the nitrogen base Uracil (U) instead of Thymine.

ATP (Adenosine TriPhosphate)

A single nucleotide functioning as an energy carrier in cells, consisting of a ribose sugar, the nitrogen base Adenine, and three phosphate groups.

Transcription

The process occurring in the nucleus where a segment of DNA is used to synthesize a complementary strand of messenger RNA (mRNA).

RNA Polymerase

An enzyme that unzips DNA at a gene and joins the sugar-phosphate backbone of newly synthesized RNA nucleotides during transcription.

Gene

A segment of DNA that specifies the amino acid sequence of a protein.

Translation

The process occurring at the ribosomes in the cytoplasm where the mRNA sequence is translated into a specific amino acid sequence to form a protein.

Codon

A group of 3 nitrogen bases on an mRNA strand that codes for a specific amino acid, such as AUG for Methionine.

Degenerate

A characteristic of the genetic code where one amino acid may be coded for by more than one codon, providing protection against harmful mutations.

Anticodon

A triplet of nitrogen bases on a tRNA molecule that is complementary to a specific codon on mRNA.

Translocation

A chromosomal mutation involving the exchange of chromosome pieces between non-homologous pairs, such as between chromosomes 21 and 14.

Point Mutation

A gene mutation, such as a substitution, where only one nitrogen base sequence is altered.

Sickle cell anemia

A genetic condition caused by a substitution in the $6^{th}$ amino acid codon of hemoglobin, changing glutamate (GAG) to valine (GUG), resulting in abnormal crystalline proteins.

Hemophilia

A genetic disease where a "stop" codon occurs early in the gene sequence, producing an incomplete, non-functional clotting factor VIII protein.

Mutagen

An environmental factor, such as chemical additives or ionizing radiation (X-rays, gamma rays, UV rays), that increases the risk of mutations.

Carcinogen

A specific type of mutagen that leads to the development of cancer.

Recombinant DNA (rDNA)

Also known as genetic modification (GM), it is DNA formed by combining the genetic material of two or more different species.