HG 6 DNA Structure, Replication, and Chromosomal Organization Vocabulary

Flashcards covering key vocabulary from lecture notes on DNA structure, replication, and related topics.

Transformation

The process by which a cell's genetic makeup is altered by the introduction of foreign DNA.

Bacteriophages

Viruses that exclusively infect bacterial cells, composed of DNA inside a protein coat.

DNA

Deoxyribonucleic acid, a nucleic acid containing the genetic instructions for all known living organisms.

RNA

Ribonucleic acid, a nucleic acid present in all living cells, acting primarily to carry instructions from DNA for controlling the synthesis of proteins.

Purines

Nitrogenous bases with a double-ring structure; includes adenine (A) and guanine (G).

Pyrimidines

Nitrogenous bases with a single-ring structure; includes cytosine (C), thymine (T) (in DNA), and uracil (U) (in RNA).

Chargaff's Rules

States that the amount of adenine (A) is equal to thymine (T) and the amount of cytosine (C) is equal to guanine (G) in DNA.

Anti-parallel Strands

Having two strands running in opposite directions, one oriented 5' to 3' and the other 3' to 5'.

Semi-conservative replication

One of the old DNA strands is conserved each time a new DNA molecule is synthesized.

Origin of replication

Areas in the genome with a high concentration of adenine (A) and thymine (T) bases where DNA replication begins.

Helicase

Unwinds and separates the double-stranded DNA.

Primase

Creates an RNA primer to initiate DNA synthesis.

DNA Polymerase

Reads the DNA and rebuilds the complementary strand.

DNA Ligase

Joins the Okazaki fragments together.

Okazaki fragments

Short fragments synthesized on the lagging strand during DNA replication.

Leading Strand

Replication proceeds continuously.

Lagging Strand

Replication occurs discontinuously in short fragments.

Bidirectional Replication

Replication begins at an origin, creating a replication bubble with two replication forks.

Nucleosome Formation

DNA wraps around eight histone proteins to form a DNA-histone complex.

Centromere

The point where spindle fibers attach and hold chromosome arms together during cell division.

Kinetochore

Disc-like structure to which spindle fibers attach during cell division, forms at the centromere.

Telomere

A cap-like structure found at the ends of chromosome arms, preventing chromosomes from unwinding and maintaining stability.

Telomerase

An enzyme that protects the ends of chromosomes during meiosis, preventing telomere shortening.

Chromosome territory

Region in the nucleus, where each chromosome has a designated.

Messenger RNA (mRNA)

Single-stranded RNA that carries the genetic message from DNA to the cytoplasm.

Transfer RNA (tRNA)

Brings amino acids to the ribosome to build proteins.

Ribosomal RNA (rRNA)

Combines with proteins to form the ribosome.