Biology vocabulary words 28/01/25

Roles of DNA (Key concept)

DNA molecule must be capable of storing and copying genetic information as well as putting that info to work in gene expression

Three components of nucleotide

Each nucleotide is made up of three components, five carbon sugar called deoxyribose, phosphate group, and a nitrogenous space nucleotides join together to form strands of DNA

Three components of DNA

DNA is made of nucleotides joined into long strands by covalent bonds.

Four nitrogen bases

How to adenine guanine cytosine and thymine refers to them as base names A G C and t. Any Base sequence is possible

Chargaffe’s rule

In any organism, the amount of Guanine should be equal to cytosine and the amount of Adanine should be equal to thymine

Franklins. Discovery of the structure of DNA.

1950s British scientist, Rosalind Franklin begin to study DNA and used x-ray diffraction to find DNA having a helix structure

Who were Watson and crick ? (key concept?)

Data in franklins x-ray pattern enabled Watson and crick to build first model that explains specific structure and properties of DNA

Double helix model (key concept)

Double helix model explains chargaff’s rule of base pairing, and how the two strands of DNA are held together

Antiparallel strands

Two strands of DNA run in opposite direction each strand carries a sequence of four letters

Hydrogen bonds

Hydrogen bonds hold Force just enough to hold two strands together weak forces, but only form with A-T and G-C

Why is a hydrogen bond needed to hold the most important molecule together?

It is important to have hydrogen bonds hold each of the molecules together because they’re stable and flexible

Base pairing

Hydrogen bonds form only with only certain base pairs AT and GC nucleotides are base pairing

Replication

Before a cell divides it copies it’s DNA into a copying process

DNA polymerase

The principal enzyme involved in DNA replication

Prokaryotic DNA replication

Replication in the most prokaryotic cells start from a single point, and proceeds in 2 directions until chromosome is copied fully

Eukaryotic DNA replication

Replication begins at dozens or hundreds of places on DNA molecules. Proceeds in both direction until each chromosome is copied.

RNA

Ribonucleic acid helped to put genetic code into action

DNA to RNA key difference

Unlike DNA, RNA likes to use sugar ribose instead of deoxyribose, RNA is single stranded and contains uracil in place of thymine

MRNA

Molecules of RNA, that carry copies of instructions to ribosomes from the nucleus in cytoplasm

rRNA

The subunits are made of several rRNA molecules, and as many as 80 proteins

tRNA

During assembly of proteins, a third type of RNA molecule carries amino acids to ribosomes and matches them to the coded MRNA message

Transcriptions

The process of copying a base sequence from DNA to RNA

RNA polymerase

Transcription is carried out by an enzyme, called RNA polymerase

Promoters

Regions of DNA with specific base sequences that can find to RNA polymerase

Exons

Remaining pieces are then spliced back together to form a final mRNA

Polypeptides

Proteins are made by joining amino acids together into Chains

Genetic code

Four bases of RNA form a kind of language with just four letters A C G T

Codon

Consist of three consecutive bases, that specify a single amino acid to be added to polypeptide chain

Translation

The decoding of an mRNA message into a protein

Anti-codon

Each tRNA molecules has three unpaired bases that are together

Operon

A group of genes that are regulated together

Differentiation

Gives rise to all of the specialized tissue and organs

Environmental influences affect on gene expression

Environmental changes affect genes incredibly environments can change a gene’s availability and can influence the epigenetic marks that are attached to chromatin