Protein Synthesis Unit Review

Biology Study Guide

Sugar-phosphate backbone

a repeating structure of “sugar-phosphate-sugar-phosphate; the nitrogenous bases are arranged as appendages along this

Translation

occurs on the surface of the ribosomes; where RNA is _____ into amino acids to make proteins

Transcription

copying DNA into RNA; where the transfer of genetic information from DNA into an RNA molecule; rewrites the DNA code into mRNA

Translation

happens at the ribosome; where the transfer of information in the RNA into a protein; switching from the nucleotide “language” to amino acid “language”

Codons

the series of 3-base words with the genetic instructions for an amino acid sequence of a polypeptide chain

Triplet code

the flow of information from gene to protein is based on the

Introns

internal, non-coding regions most genes of plants & animals include these

Exons

the coding regions; the parts of a gene that are expressed as amino acids

RNA Splicing

the cutting & pasting process; this is catalyzed by a complex of proteins and smaller RNA molecules

messenger RNA (mRNA)

conveys genetic information from DNA to the translation

a nitrogenous base, a 5-carbon sugar, and a phosphate group

What’s the 3 main units for the structure of DNA/RNA?

Hemoglobin

a protein in RBC’s that carries O_²

Gene

an order of DNA nucleotides that direct the synthesis (making) of a specific protein

Location of ribosomes

structures that float freely in the cytosol and are bound to the endoplasmic reticulum (rough ER)

Ribosomes

these molecular machines found in ALL living cells; they function as protein factories to translate genetic code from mRNA into chains of amino acids to build proteins

rRNA (ribosomal RNA)

What are ribosomes made of?

Primary, secondary, tertiary, and quaternary

What are the 4 protein shapes? (ex. the structure determines the function)

in the ribosome

Where does protein synthesis occur?

Anticodons

allows the tRNA to bind to a specific mRNA codon; these are complementary in sequence

mutation

a change in the nucleotide sequence of DNA

Deletions and insertions

alter the reading frame of the mRNA, so that nucleotides are grouped into different codons

Base substitution

the replacement of one nucleotide with another

High-radiation and chemicals

What’s are 2 examples of a mutagen?

nucleotides

the monomer unit of DNA and RNA

proteins

determines the phenotype of an organism

in the nucleus

Where does transcription occur?

Transfer RNA (tRNA)

in order to convert the 3-letter words (codons) of nucleic acids to ONE-word amino acids, a cell employs a molecular in

AUG - methionine

What mRNA code signals the “START” of transcription?

UAA, UAG, UGA

What are the 3 “STOP” mRNA codons that signal the end of translation?

T > A , A > U, G > C, C > G

What’s the base pairing from DNA to mRNA? (T >_ ) (A > _) (G > _) (C > _)

A > U, U > A, C > G, G > C

What’s the base pairing from mRNA to tRNA? (A >_ ) (U > _) (C > _) (G > _)