BIOL 1010 (But you don't have to pay for Quizlet)

Nucleic acids

Information molecules of cells that store and transmit genetic information; include DNA and RNA.

DNA (Deoxyribonucleic acid)

The primary genetic material in most organisms that stores hereditary information.

RNA (Ribonucleic acid)

A nucleic acid involved in gene expression and protein synthesis.

Chromosomes

Large DNA molecules that organize genes within cells.

Genome

The complete set of DNA in an organism.

Proteomics

The large-scale study of all proteins produced by an organism.

Nucleotide

The building block of DNA and RNA consisting of sugar, phosphate, and nitrogenous base.

Nitrogenous base

A nitrogen-containing molecule that forms part of a nucleotide (A, T, C, G).

Deoxyribose

The five-carbon sugar found in DNA nucleotides.

Phosphate group

The component of nucleotides that forms the backbone of DNA.

Sugar-phosphate backbone

The repeating structural framework of DNA made from sugars and phosphates.

Double helix

The twisted ladder shape of DNA.

Base pairing

The pairing of nitrogenous bases (A-T, C-G) through hydrogen bonds.

Hydrogen bond

A weak bond that holds complementary DNA bases together.

Covalent bond

A strong chemical bond linking nucleotides in DNA.

Complementary strands

Two DNA strands whose bases pair specifically with one another.

Antiparallel strands

DNA strands that run in opposite directions (5′→3′ and 3′→5′).

5′ end

The DNA strand end with a free phosphate group attached to the 5′ carbon.

3′ end

The DNA strand end with a free hydroxyl group attached to the 3′ carbon.

DNA replication

The process by which DNA copies itself before cell division.

Semiconservative replication

A model where each new DNA molecule contains one old strand and one new strand.

Leading strand

The DNA strand synthesized continuously during replication.

Lagging strand

The DNA strand synthesized in short fragments during replication.

Okazaki fragments

Short DNA segments produced on the lagging strand.

DNA polymerase

Enzyme that adds nucleotides to synthesize DNA.

Helicase

Enzyme that unwinds the DNA double helix.

Purines

Double-ring nitrogenous bases (adenine and guanine).

Pyrimidines

Single-ring nitrogenous bases (cytosine and thymine).

Central dogma

The flow of genetic information from DNA to RNA to protein.

Transcription

The process of copying DNA into RNA.

Translation

The process of converting RNA information into protein.

Genetic code

The rules that determine how codons specify amino acids.

Codon

A three-nucleotide sequence that codes for an amino acid.

Triplet code

The three-base system used to code for amino acids.

Gene

A DNA segment that encodes a functional product such as a protein.

Phenotype

The observable characteristics of an organism.

Mutation

A change in the DNA nucleotide sequence.

Base substitution

A mutation where one nucleotide is replaced with another.

Insertion mutation

A mutation caused by adding nucleotides into DNA.

Deletion mutation

A mutation caused by removing nucleotides from DNA.

Frameshift mutation

A mutation that shifts the reading frame of codons.

Genetic variation

Differences in DNA among individuals.

Mutagen

An environmental factor that causes mutations.

Sickle cell anemia

A disease caused by a single base substitution in the hemoglobin gene.

Hemoglobin

A protein in red blood cells that carries oxygen.

DNA packaging

The folding and organization of DNA to fit inside the nucleus.

Amino acids

The building blocks of proteins.

Ribosome

The cellular structure where proteins are synthesized.

mRNA

Messenger RNA that carries genetic instructions from DNA to ribosomes.

tRNA

Transfer RNA that brings amino acids to ribosomes.

rRNA

Ribosomal RNA that forms part of the ribosome structure.

RNA polymerase

The enzyme that synthesizes RNA from a DNA template.

Protein

A molecule made of amino acids that performs cellular functions.

Chargaff’s rules

The rules stating that A=T and C=G in DNA.

Exons

The coding portions of genes that remain in mature RNA.

Introns

Noncoding sections removed from RNA transcripts.

Primary RNA transcript

The initial RNA produced during transcription before processing.

GTP cap

A modified nucleotide added to the 5′ end of mRNA.

Poly-A tail

A chain of adenine nucleotides added to the 3′ end of mRNA.

Spliceosome

A molecular complex that removes introns from RNA.

RNA processing

The modification of RNA transcripts before translation.

Karyotype

The number and visual appearance of chromosomes in a cell.

Autosomal chromosome

A chromosome that is not involved in determining sex.

Sex chromosomes

Chromosomes that determine biological sex (X and Y).

Diploid (2n)

A cell containing two sets of chromosomes.

Haploid (n)

A cell containing one set of chromosomes.

Homologous chromosomes

A pair of chromosomes with the same genes but possibly different alleles.

Alleles

Different forms of the same gene.

Mitosis

A cell division producing two genetically identical daughter cells.

Cytokinesis

The division of cytoplasm after nuclear division.

Cleavage furrow

The indentation that forms in animal cells during cytokinesis.

Cell plate

A structure forming in plant cells during cytokinesis.

Meiosis

A specialized cell division producing haploid gametes.

Gametes

Sex cells such as sperm and egg.

Fertilization

The fusion of two gametes to form a zygote.

Zygote

The fertilized egg cell.

Somatic cells

Body cells that are not involved in reproduction.

Germ cells

Cells that produce gametes.

Prophase

The stage when chromosomes condense and spindle forms.

Metaphase

The stage when chromosomes align in the middle of the cell.

Anaphase

The stage when sister chromatids separate.

Telophase

The stage when nuclear membranes reform.

Interphase

The stage when the cell grows and replicates DNA.

Sister chromatids

Identical copies of a chromosome connected at the centromere.

Centromere

The region where sister chromatids attach.

Spindle fibers

Microtubules that move chromosomes during cell division.

Operon

A cluster of genes regulated together in prokaryotes.

lac operon

A gene system regulating lactose metabolism in bacteria.

trp operon

A gene system regulating tryptophan synthesis.

Repressor

A protein that blocks transcription.

Activator

A protein that increases transcription.

Promoter

A DNA region where transcription begins.

Operator

A DNA region where regulatory proteins bind.

Inducer

A molecule that activates gene expression.

Beta-galactosidase

Enzyme that breaks lactose into glucose and galactose.

Differential gene expression

The process where different cells express different genes.

DNA packing

The condensation of DNA around proteins.

Transcription factor

A protein that controls gene transcription.

Enhancer

A DNA region that increases transcription levels.

Silencer

A DNA region that represses transcription.