Bio U 12

Central Dogma

Genetic information flow from DNA to RNA to Proteins, coined by Francis Crick.

7 Different functions of proteins

Various roles of proteins including structural, contractile, defensive, signal, receptor, transport, storage, and enzymes.

DNA Vs

Both are nucleic acids with nucleotides, containing adenine, cytosine, and guanine bases, and have a phosphate backbone.

DNA Vs

DNA is double-stranded, contains thymine, located in the nucleus; RNA is usually single-stranded, uses uracil, found in the nucleus and cytoplasm, and has ribose.

Types of RNA and Their Functions

mRNA carries genetic info, rRNA is part of ribosomes, tRNA transfers amino acids during protein synthesis.

Location and Function of Ribosomes

Bound ribosomes synthesize external proteins, free ribosomes synthesize internal proteins.

mRNA Codons

Sequences of three nucleotides carrying genetic info for protein synthesis.

Transcription

Process of making RNA from DNA, occurs in the nucleus of eukaryotic cells and cytoplasm of prokaryotic cells.

RNA Polymerase

Enzyme copying DNA to build RNA molecules.

Translation

Synthesizing proteins from mRNA at the ribosome in the cytoplasm.

Start Codon and Stop Codons

AUG signals start, UAA, UAG, UGA signal stop of protein synthesis.

Redundancy of the Genetic Code

Multiple codons for most amino acids, providing error tolerance and evolutionary flexibility.

Mutations

Point, frameshift, silent, missense, and nonsense mutations altering DNA sequences, caused by hereditary or acquired factors like mutagens.