Biology - Nucleic Acids

Flashcards covering key vocabulary and concepts related to nucleic acids, DNA, RNA, and their structure and function.

Nucleic acids

Very large molecules constructed by linking together nucleotides to form a polymer. They are the genetic material of a cell and determine how both individual cells and entire organisms will develop and function. They function as the basic unit of inheritance by coding for the synthesis of proteins.

Nucleotide

Consists of three parts: a sugar which has five carbon atoms (pentose sugar), a phosphate group which is the acidic, negatively charged part of nucleic acids, and a base that contains nitrogen.

Condensation polymerisation

Nucleotides (monomer) join to form a long single chain of nucleic acids (polymer). Involves the removal of water (output). Requires the input of energy (ATP). Creates a phosphodiester bond.

DNA Structure

A structure made of anti-parallel strands of nucleotides linked by hydrogen bonding between complementary base pairs. The two strands are parallel but run in opposite directions.

Complementary base pairing

Adenine (A) is paired with Thymine (T) with two hydrogen bonds, and Guanine (G) is paired with Cytosine (C) with three hydrogen bonds.

Watson and Crick

Discovered the structure of DNA using model making.

DNA vs RNA: Sugar

DNA contains deoxyribose. RNA contains ribose.

DNA vs RNA: Bases

DNA contains Adenine, Thymine, Guanine, and Cytosine. RNA contains Adenine, Uracil, Guanine, and Cytosine.

DNA vs RNA: Strands

DNA is double-stranded (two polymers) forming a double helix. RNA is single-stranded (one polymer) and may coil into shapes.

mRNA (Messenger RNA)

Shape: linear. Function: Carries the code (genetic information) for protein synthesis from the nucleus to the ribosome.

tRNA (Transfer RNA)

Shape: cloverleaf. Function: Carries a specific amino acid to the ribosome for protein synthesis.

rRNA (Ribosomal RNA)

Shape: globular. Function: Structural component of the ribosome (combines with protein) which is the site of protein synthesis.