BIOFOUND 4.4 Gene Expression Part 1

Genome

The complete set of genetic material (DNA) in an organism.

Gene

A segment of DNA that contains instructions for making a specific protein or RNA.

Gene Expression

The process by which the information in a gene is used to create a functional product, typically a protein.

Why are proteins important to cells, and why must cells convert genetic instructions into proteins?

Proteins are essential for various cell functions, including structure, enzyme activity, and regulation of processes. Cells must turn the instructions in their genes into proteins to carry out these vital functions.

Central Dogma

Describes the flow of genetic information in cells

Transcription

The process where a DNA sequence is copied into RNA.

Translation

The process where the RNA sequence is used to assemble amino acids into a protein.

Coding strand

The strand of DNA that has the same sequence as the RNA (except with T instead of U).

Template strand

The strand of DNA that serves as the template for RNA synthesis.

RNA polymerase

The enzyme that synthesizes RNA from a DNA template during transcription.

DNA

Double-stranded, contains deoxyribose sugar, and uses thymine (T) as a base.

RNA

Single-stranded, contains ribose sugar, and uses uracil (U) instead of thymine (T).

DNA

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

RNA

Adenine (A) pairs with Uracil (U), and Cytosine (C) pairs with Guanine (G).

Prokaryotic cells

Both transcription and translation occur in the cytoplasm.

Eukaryotic cells

Transcription occurs in the nucleus, and translation occurs in the cytoplasm.

Protein structure

A protein is made up of amino acids linked together by peptide bonds.

Protein sequence

The specific order of amino acids in a protein, determined by the sequence of codons in the RNA.

Codon

A sequence of three nucleotides in mRNA that codes for a specific amino acid.

what does the genetic code do?

The genetic code maps each codon to its corresponding amino acid.

MET codon (AUG)

The start codon, which signals the beginning of translation and codes for methionine.

STOP codons (UAA, UAG, UGA)

Signal the end of translation, causing the ribosome to release the completed protein.

Translation

The process where ribosomes read the mRNA codons and use tRNA to add the corresponding amino acids to the growing protein chain.

tRNA

Molecules that carry amino acids to the ribosome, matching their anticodon with the codon in the mRNA.

How do you write the complementary DNA strand for a given genetic sequence?

Given a genetic sequence, write the complementary DNA strand by replacing A with T, T with A, C with G, and G with C.

How do you transcribe a template DNA sequence into an RNA sequence?

Given a template DNA sequence, transcribe it into an RNA sequence by replacing T with U (thymine becomes uracil), while keeping A, C, and G the same.