ATI TEAS Genetic Material and the Structure of Proteins

Genetic material

DNA that stores hereditary information and directs protein synthesis

Chromosomes

Structures made of tightly coiled DNA wrapped around histone proteins

Prokaryotic chromosomes

Single circular chromosome found in bacteria

Eukaryotic chromosomes

Multiple linear chromosomes found in cells with a nucleus

Human chromosome number

46 chromosomes (23 pairs)

Genes

Segments of DNA that code for proteins or regulate protein production

Structural genes

Genes that code directly for proteins

Regulatory genes

Genes that control gene expression by turning genes on or off

Gene expression

Process of activating specific genes to produce proteins

DNA (deoxyribonucleic acid)

Double-helix molecule that contains genetic instructions

Structure of DNA

Double helix made of a sugar-phosphate backbone and nitrogen bases

Nucleotides

Building blocks of DNA made of sugar, phosphate, and a nitrogen base

Nitrogen bases in DNA

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

Base pairing rules

Adenine pairs with thymine, and guanine pairs with cytosine

Complementary strands

DNA strands that follow base-pairing rules

Hydrogen bonds

Weak bonds that hold complementary DNA bases together

Antiparallel strands

DNA strands run in opposite directions (5' to 3' and 3' to 5')

Codon

Sequence of three nucleotides that codes for an amino acid or stop signal

Chromatid

One of two identical copies of a replicated chromosome

DNA replication

Process of copying DNA before cell division

Mutation

Permanent change in DNA sequence (substitution, insertion, deletion)

Effects of mutations

Can be harmless, harmful, or cause diseases

RNA (ribonucleic acid)

Single-stranded molecule involved in protein synthesis

RNA bases

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

Difference between DNA and RNA

RNA is single-stranded and uses uracil instead of thymine

mRNA (messenger RNA)

Carries genetic instructions from DNA to ribosomes

tRNA (transfer RNA)

Brings amino acids to ribosomes during protein synthesis

rRNA (ribosomal RNA)

Forms part of ribosomes and helps assemble proteins

Transcription

Process of copying DNA into mRNA in the nucleus

Template strand

DNA strand used to build mRNA during transcription

Translation

Process where ribosomes read mRNA to build proteins

Ribosomes

Organelles that assemble proteins using mRNA instructions

Anticodon

Three-base sequence on tRNA that pairs with an mRNA codon

Peptide bond

Bond that links amino acids together in a protein

Protein synthesis

Process of making proteins through transcription and translation

Genome

Complete set of genetic material in an organism

DNA to protein pathway

DNA is transcribed into RNA, which is translated into protein

Gene to protein relationship

Genes contain codons that determine amino acid sequence

Cell specialization

Different cells express different genes to produce specific proteins