Chapters 10 and 11 Study Guide: DNA, RNA, and Protein Synthesis

Comprehensive vocabulary flashcards covering DNA/RNA structure, DNA replication, transcription, and translation based on study questions for Chapters 10 and 11.

Monomers of DNA and RNA

Nucleotides.

Nucleotide Components

A three-part structure consisting of a phosphate group, a five-carbon sugar (pentose), and a nitrogenous base.

DNA Bases

Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).

RNA Bases

Adenine (A), Guanine (G), Cytosine (C), and Uracil (U).

Purines

Nitrogenous bases with a double-ring structure, specifically Adenine (A) and Guanine (G).

Pyrimidines

Nitrogenous bases with a single-ring structure, including Cytosine (C), Thymine (T), and Uracil (U).

Base Pairing Rules

In DNA, A pairs with T and G pairs with C; in RNA, A pairs with U and G pairs with C.

Chemical differences: DNA vs RNA

DNA contains the sugar deoxyribose and the base thymine, while RNA contains the sugar ribose and the base uracil.

$1'$ Carbon

The carbon atom of the nucleotide sugar to which the nitrogenous base is attached.

$2'$ Carbon

The carbon atom that determines the sugar type; it has an $-OH$ group in ribose (RNA) and an $-H$ in deoxyribose (DNA).

$3'$ Carbon

The carbon atom of the nucleotide sugar that has a hydroxyl ($-OH$) group used to bond with the next nucleotide's phosphate group.

$5'$ Carbon

The carbon atom of the nucleotide sugar to which the phosphate group is attached.

Sugar-Phosphate Backbone

The alternating chain of sugar and phosphate groups that forms the structural support of a DNA or RNA strand.

Double Stranded DNA Structure

A double helix composed of two antiparallel strands held together by hydrogen bonds between complementary nitrogenous bases.

Semiconservative Replication

The mechanism of DNA replication in which each daughter DNA molecule consists of one original parental strand and one newly synthesized strand.

Origin of Replication

Specific sequences of DNA where the process of replication is initiated.

Direction of DNA Synthesis

New DNA strands are always synthesized in the $5' \rightarrow 3'$ direction.

Leading Strand

The DNA strand synthesized continuously toward the replication fork.

Lagging Strand

The DNA strand synthesized discontinuously in short segments (Okazaki fragments) away from the replication fork.

DNA Polymerase

The primary enzyme that assembles new DNA nucleotides to build a complementary strand during replication.

DNA Ligase

The enzyme responsible for sealing gaps between DNA fragments, such as joining Okazaki fragments on the lagging strand.

Transcription

The process of synthesizing an RNA molecule using a DNA template.

RNA Polymerase

The enzyme that reads the DNA template strand and assembles a complementary RNA sequence.

mRNA (Messenger RNA)

RNA that carries the genetic code from the DNA in the nucleus to the ribosome for translation into protein.

tRNA (Transfer RNA)

RNA that transports specific amino acids to the ribosome and matches them to mRNA codons via its anticodon.

rRNA (Ribosomal RNA)

The structural and functional component of ribosomes that catalyzes the formation of peptide bonds.

Promoter and Terminator

DNA sequences that signal RNA Polymerase where to begin transcription (promoter) and where to stop (terminator).

mRNA Processing

Modifications occurring in the nucleus including the addition of a $5'$ cap, a poly-A tail, and RNA splicing.

Introns

Non-coding regions of a primary RNA transcript that are removed during splicing.

Exons

The coding regions of an RNA transcript that are joined together and eventually translated into protein.

Translation

The process by which ribosomes use the mRNA sequence to assemble a polypeptide chain.

Stop Codon

An mRNA sequence (UAA, UAG, or UGA) that signals the ribosome to terminate translation.

DNA Mutations

Changes in the nucleotide sequence of DNA, which can include substitutions, insertions, deletions, or frameshifts.