Chapter 12: From DNA to Protein

Flashcards for review of molecular biology concepts.

Central Dogma of Molecular Biology

DNA -> RNA -> Protein: Describes the flow of genetic information.

DNA Structure

Double helix made of nucleotides, including a phosphate group, 5-carbon sugar, and nitrogenous base.

DNA Replication

Process of DNA duplicating itself, occurring in the S phase of the cell cycle.

RNA Structure

Single-stranded, with ribose sugar and uracil instead of thymine.

Transcription

RNA synthesis using DNA as a template, catalyzed by RNA polymerase.

Genetic Code

Set of rules by which information encoded in genetic material (DNA or RNA) is translated into proteins by living cells.

Translation

Protein synthesis from an RNA template.

Mutation

Change in the nucleotide sequence of DNA.

Gene Expression

Multistep process where genetic information encoded by a gene is converted into a structural or functional part of a cell.

Rosalind Franklin

Scientist who created the X-ray photo of DNA that helped Watson and Crick describe the DNA molecule.

Watson and Crick

Scientists who described the DNA molecule using Franklin's X-ray photo.

Nucleotide

Made of a phosphate group, a 5-carbon sugar, and a nitrogenous base.

Purines

Adenine and guanine.

Pyrimidines

Cytosine, thymine, and uracil.

Chargaff’s Rule

Adenine pairs with thymine; guanine pairs with cytosine.

S Phase

Phase in interphase of cell cycle where DNA replication takes place.

Replication Fork

Y-shaped region of replicating DNA molecules where new strands are growing.

Replication Bubble

Region of replicating DNA.

Helicase

Unwinding protein that recognizes and binds origin of replication.

DNA Gyrase

Topoisomerase that assists in unwinding by inducing supercoiling.

SSB Proteins

Single-stranded DNA binding proteins that protect DNA strands from cleavage.

Primase

Enzyme that synthesizes a short complementary stretch of RNA.

DNA Polymerase III

Enzyme that begins DNA synthesis.

DNA Polymerase I

Enzyme that removes RNA primer and fills in the gap with DNA.

DNA Ligase

Enzyme that closes the final gap between new DNA strands.

mRNA

Template for protein synthesis.

rRNA

Structural component of ribosome.

tRNA

Adapter molecule that transfers amino acids.

RNA Polymerase

Assembles RNA by linking RNA nucleotides into a chain.

Promoter Sequence

Where RNA polymerase binds to DNA to initiate transcription.

Introns

Nucleotide sequences that are removed from a new RNA.

Exons

Sequences that stay in the RNA.

Codon

Sequence of three mRNA nucleotides that codes for a specific amino acid.

Anticodon

tRNA with an anticodon complementary to an mRNA codon, and a binding site for the amino acid specified by that codon.

Initiation Complex

A small ribosomal subunit binds to mRNA. The anticodon of initiator tRNA base-pairs with the start codon (AUG) of mRNA. A large ribosomal subunit joins the small ribosomal subunit.

Mutations

Small-scale changes in the nucleotide sequence of a cell’s DNA.

Base-pair Substitution

May result in a premature stop codon or a different amino acid in a protein product.

Deletion or Insertion

Can cause the reading frame of mRNA codons to shift, changing the genetic message.

Transposable Elements

Segments of DNA that can insert themselves anywhere in a chromosome.

Spontaneous Mutations

Uncorrected errors in DNA replication.

Central Dogma of Molecular Biology

DNA -> RNA -> Protein: Describes the flow of genetic information.

DNA Structure

Double helix made of nucleotides, including a phosphate group, 5-carbon sugar, and nitrogenous base.

DNA Replication

Process of DNA duplicating itself, occurring in the S phase of the cell cycle. Involves replication fork, replication bubble, helicase, DNA gyrase, SSB proteins, primase, DNA polymerase III, DNA polymerase I, and DNA ligase.

RNA Structure

Single-stranded, with ribose sugar and uracil instead of thymine.

Transcription

RNA synthesis using DNA as a template, catalyzed by RNA polymerase. Begins at the promoter sequence. Produces introns and exons.

Genetic Code

Set of rules by which information encoded in genetic material (DNA or RNA) is translated into proteins by living cells.

Translation

Protein synthesis from an RNA template. Involves mRNA, rRNA, tRNA, codons, anticodons, and initiation complex.

Mutation

Change in the nucleotide sequence of DNA.

Gene Expression

Multistep process where genetic information encoded by a gene is converted into a structural or functional part of a cell.

Rosalind Franklin

Scientist who created the X-ray photo of DNA that helped Watson and Crick describe the DNA molecule.

Watson and Crick

Scientists who described the DNA molecule using Franklin's X-ray photo.

Nucleotide

Made of a phosphate group, a 5-carbon sugar, and a nitrogenous base.

Purines

Adenine and guanine.

Pyrimidines

Cytosine, thymine, and uracil.

Chargaff’s Rule

Adenine pairs with thymine; guanine pairs with cytosine.

S Phase

Phase in interphase of cell cycle where DNA replication takes place.

Replication Fork

Y-shaped region of replicating DNA molecules where new strands are growing.

Replication Bubble

Region of replicating DNA.

Helicase

Unwinding protein that recognizes and binds origin of replication.

DNA Gyrase

Topoisomerase that assists in unwinding by inducing supercoiling.

SSB Proteins

Single-stranded DNA binding proteins that protect DNA strands from cleavage.

Primase

Enzyme that synthesizes a short complementary stretch of RNA.

DNA Polymerase III

Enzyme that begins DNA synthesis.

DNA Polymerase I

Enzyme that removes RNA primer and fills in the gap with DNA.

DNA Ligase

Enzyme that closes the final gap between new DNA strands.

mRNA

Template for protein synthesis.

rRNA

Structural component of ribosome.

tRNA

Adapter molecule that transfers amino acids.

RNA Polymerase

Assembles RNA by linking RNA nucleotides into a chain.

Promoter Sequence

Where RNA polymerase binds to DNA to initiate transcription.

Introns

Nucleotide sequences that are removed from a new RNA.

Exons

Sequences that stay in the RNA.

Codon

Sequence of three mRNA nucleotides that codes for a specific amino acid.

Anticodon

tRNA with an anticodon complementary to an mRNA codon, and a binding site for the amino acid specified by that codon.

Initiation Complex

A small ribosomal subunit binds to mRNA. The anticodon of initiator tRNA base-pairs with the start codon (AUG) of mRNA. A large ribosomal subunit joins the small ribosomal subunit.

Mutations

Small-scale changes in the nucleotide sequence of a cell’s DNA. Includes base-pair substitution, deletion, insertion, transposable elements, and spontaneous mutations.

Base-pair Substitution

May result in a premature stop codon or a different amino acid in a protein product.

Deletion or Insertion

Can cause the reading frame of mRNA codons to shift, changing the genetic message.

Transposable Elements

Segments of DNA that can insert themselves anywhere in a chromosome.

Spontaneous Mutations

Uncorrected errors in DNA replication.