UNIT 1 - A 1.2 - Nucleic Acids Flashcards
Information being passed down from one generation to another is in the form of what?
DNA
What does DNA stand for?
Deoxyribonucleic acid
Where do mutations occur?
Withing DNA
What are the four nitrogenous bases in DNA
adenine, thymine, cytosine, guanine
What are genetic messages/genes?
the sequences of nitrogenous bases
What are the genetic messages code for?
amino acids
What are amino acids known as?
The building blocks of proteins
What is the cell’s identity and function determined by?
the proteins it is able to synthesize
Why are viruses not considered alive?
Because they cannot survive without a cell of a living organism
When do viruses’s nucleic acid (RNA or DNA) become active?
When they infect a cell
What is the sole function of a virus
To reproduce itself
In the same order, what does the circle, pentagon, and rectangle represent in diagrams of nucleotides?
Phosphates, pentose sugars, and bases
What are both DNA and RNA considered?
polymers of nucleotides
What are polymers?
Repeating nucleotides within a larger molecule
What do nucleotides consist of?
One phosphate group, one five-carbon monosaccharide (pentose sugar), and a nitrogenous base
What kind of bonds occur at specific locations in order to produce a polymer?
Covalent bonds
How is a chain of nucleotides formed?
The pentose sugar of one nucleotide is covalently bonded to the phosphate group of the next nucleotide
What is found at the two ends of a nucleic acid polymer?
One phophate group with only one bond to a sugar at one end and a pentose sugar with only one bond to a single phosphate on the other end
Nucleotides bond to form a polymer as a result of what kind of reaction?
condensation reactions
Why are nucleic acid polymers made of nucleotides stable?
Because covalent bonds are relatively strong as they require quite a bit of energy to break
What are the four possible nitrogenous bases in RNA?
Adenine (A), Uracil (U), Cytosine (C), and Guanine (G)
What are the four possible nitrogenous bases in DNA?
Adenine (A), Thymine (T), Cytosine (C), and Guanine (G)
What pentose sugar does RNA contain?
Ribose
What pentose sugar does DNA contain?
Deoxyribose
How many different nucleotides are there in total?
8
When is RNA formed?
When nucleotides become bonded together in very specific sequences
How are nucleotides joined together?
Condensation reactions
What are condensation reactions between?
The pentose sugar of one nucleotide and the phosphate group of the next nucleotide
What do condensation reactions release?
A water molecule
What is the rule for determining the number of water molecules released during an RNA molecule’s synthesis?
The number of water molecules released is the same as the number of condensation reactions that took place which is one less than the number of nucleotides in the RNA molecule
What are the two strands/chains in DNA connected by?
Hydrogen bonds
What are the nitrogenous bases pairs in DNA?
Adenine (A) with thymine (T) and cytosine (C) with guanine (G)
What are complementary base pairs?
The nitrogenous base pairs: adenine with thymine and cytosine with guanine
Why are the two strands of DNA said to be antiparallel to each other?
Because the two strands are upside down in comparison to each other but parallel
What do all nucleotides of DNA consist of?
Deoxyribose sugar
What do all nucleotides of RNA consist of?
ribose sugar
What is the shape of DNA?
double helix
What acts as the permanent genetic code of a cell/organism?
DNA
What is the exception to RNA not containing a permanent genetic code?
RNA viruses