DNA Structure, Replication, and Protein Synthesis

Flashcards to help review key concepts related to DNA structure, DNA replication, and Protein Synthesis

What is the process of protein synthesis?

The process of reading the instructions in DNA to make a polypeptide.

What are the four levels of protein structure?

Primary structure, Secondary structure, Tertiary structure, Quaternary structure.

Where is DNA located and where are proteins made?

DNA is located in the nucleus, while proteins are made in ribosomes.

What are the two steps of protein synthesis?

Transcription and Translation.

What is the role of mRNA in protein synthesis?

mRNA copies instructions in DNA and carries these to the ribosomes in the cytoplasm.

What is the role of tRNA in protein synthesis?

tRNA binds and carries specific amino acids to the ribosome.

What is the function of rRNA?

Along with proteins, rRNA makes up the ribosome and helps catalyze the formation of peptide bonds.

What is Transcription in protein synthesis?

The process where DNA is copied into a complementary strand of mRNA.

What happens during RNA splicing?

Introns are removed and exons are spliced together, allowing for different combinations of exons to create multiple polypeptides from one gene.

What is a codon?

A set of 3 nucleotides on the mRNA.

What is the purpose of Translation?

To read/follow the instructions carried on the mRNA to make a polypeptide.

What starts and ends the process of Translation?

Starts with mRNA and ends with a polypeptide.

What is gene expression?

A regulated process that turns genes 'on' and 'off' critical for cell differentiation.

What is the difference between mutation and epigenetics?

A mutation is a change in a DNA sequence, while epigenetics modify gene expression without changing the DNA sequence itself.

What does RNA Polymerase do?

It binds to the DNA promoter, unzips the gene, and matches RNA nucleotides with exposed DNA nucleotides during transcription.

What is the significance of the TATA box?

It serves as a signal for RNA Polymerase to start transcription.

What is the direction of RNA synthesis?

RNA is made in the 5’-3’ direction.

What are transcription factors?

Regulatory proteins that control gene activity.

What is a stop codon?

A codon that signals the termination of translation, ending the polypeptide chain.

What is the macromolecule that holds genetic material and contains genes for protein synthesis?

Nucleic acids.

What are the two types of nucleic acids?

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

What sugar is found in DNA and RNA?

Deoxyribose in DNA and ribose in RNA.

What are the two types of nitrogenous bases in DNA?

Purines (adenine and guanine) and pyrimidines (cytosine and thymine).

Who discovered the structure of DNA and in which year?

James Watson and Francis Crick in 1953.

What shape describes the structure of DNA?

Double helix.

What are the complementary base pairing rules for DNA?

Adenine (A) pairs with Thymine (T) and Cytosine (C) pairs with Guanine (G).

What does it mean for DNA strands to be antiparallel?

The strands run in opposite directions, with one running 5' to 3' and the other 3' to 5'.

What is the process of making an identical copy of DNA called?

DNA Replication.

What enzyme unzips the DNA during replication?

Helicase.

What is the function of DNA Polymerase?

It adds complementary nucleotides to template strands during DNA replication.

What are Okazaki fragments and where are they found?

Short pieces of DNA created on the lagging strand during DNA replication.

What is Semi-Conservative Replication?

The process where each new DNA molecule consists of one old strand and one new strand.

What type of bond holds the nitrogen bases together in DNA?

Weak hydrogen bonds.

What type of bonds connect the sugar and phosphate backbone in DNA?

Strong covalent bonds.

What is the role of DNA ligase during replication?

It seals gaps between fragments of DNA by forming phosphodiester bonds.

explain the process of dna replication in a few short sentences

DNA replication is the process by which a cell makes an identical copy of its DNA. It begins with the unwinding of the double helix structure by enzymes called helicases, which separate the two strands of DNA. Each strand then serves as a template for the formation of new complementary strands, facilitated by DNA polymerase enzymes that add nucleotides in a specific order. The result is two identical DNA molecules, each comprising one original and one newly synthesized strand.

explain the process of protein synthesis in a few short sentences

Protein synthesis is the process through which cells create proteins, which are essential for cell function and structure. It occurs in two main stages: transcription and translation. During transcription, the DNA sequence of a gene is copied into messenger RNA (mRNA) in the nucleus. The mRNA then travels to the ribosome, where translation occurs, involving transfer RNA (tRNA) that brings specific amino acids to the ribosome to build a polypeptide chain according to the sequence of codons on the mRNA. Once the polypeptide chain is complete, it folds into a functional protein.