1.5 (biological molecules) Flashcards
what are the two types of nucleic acid
- deoxyribonucleic acid (DNA)
- ribonucleic acid (RNA)
DNA and RNA are both needed to
- build proteins
- which are essential for the proper functioning of cells
the function of DNA is to
hold or store genetic information
DNA is the molecule that contains
the instructions for the growth and development of all organisms
the function of RNA is to
- transfer the genetic code found in DNA out of the nucleus
- and carry it to the ribosomes in the cytoplasm
ribosomes are where
- proteins are produced
- they ‘read’ the RNA to make polypeptides (proteins) in a process known as translation
both DNA and RNA are
polymers
both DNA and RNA are polymers that are made up of many
repeating units called nucleotides
each nucleotide is formed from
- a pentose sugar (a sugar with 5 carbon atoms)
- a nitrogen-containing (nitrogenous) organic base
- a phosphate group
the components of a DNA nucleotide are
- a deoxyribose sugar with hydrogen at the 2’ position
- a phosphate group
- one of four nitrogenous bases - adenine (A), cytosine(C), guanine(G) or thymine(T)
the components of an RNA nucleotide are
- a ribose sugar with a hydroxyl (OH) group at the 2’ position
- a phosphate group
- one of four nitrogenous bases - adenine (A), cytosine(C), guanine(G) or uracil (U)
the presence of the 2’ hydroxyl group makes RNA more
susceptible to hydrolysis
makes RNA more susceptible to hydrolysis
the presence of the 2’ hydroxyl group
the presence of the 2’ hydroxyl group makes RNA more susceptible to hydrolysis, this is why DNA is the
- storage molecule
- and RNA is the transport molecule with a shorter molecular lifespan
DNA nucleotide diagram
RNA nucleotide diagram
the nitrogenous base molecules that are found in the nucleotides of DNA are
A, T, C, G
the nitrogenous base molecules that are found in the nucleotides of RNA are
A, U, C, G
the nitrogenous base molecules that are found in the nucleotides of DNA (A, T, C, G) and RNA (A, U, C, G) occur in two structural forms which are
- purines
- pyrimidines
the bases adenine and guanine are
purines
what is the structure of purines
double ring structure
the bases cytosine, thymine and uracil are
pyrimidines
what is the structure of pyrimidines
single ring structure
which bases are purines
- adenine
- guanine
which bases are pyrimidines
- cytosine
- thymine
- uracil
phosphate group diagram
the two types of pentose sugar diagram
the two structural forms of nitrogenous base diagram
what is the pentose sugar of the DNA nucleotide
deoxyribose
what is the pentose sugar of the RNA nucleotide
ribose
what are the nitrogenous bases of the DNA nucleotide
- adenine
- thymine
- cytosine
- guanine
what are the nitrogenous bases of the RNA nucleotide
- adenine
- uracil
- cytosine
- guanine
DNA and RNA are polymers (polynucleotides), meaning that they are made up of many nucleotides joined together in
long chains
separate nucleotides are joined via
condensation reactions
these condensation reactions occur between the
- phosphate group of one nucleotide
- and the pentose sugar of the next nucleotide
a condensation reaction between two nucleotides forms a
phosphodiester bond
it is called a phosphodiester bond because it consists of a
- phosphate group
- and two ester bonds (phosphate with double bond oxygen attached - oxygen - carbon)
the chain of alternating phosphate groups and pentose sugars produced as a result of many phosphodiester bonds is known as the
sugar-phosphate backbone (of the DNA or RNA molecule)
a section of a single polynucleotide strand showing a phosphodiester bond diagram
DNA molecules are made up of two polynucleotide strands lying side by side, running in opposite directions – the strands are said to be
antiparallel
each DNA polynucleotide strand is made up of alternating
deoxyribose sugars and phosphate groups
each DNA polynucleotide strand is made up of alternating deoxyribose sugars and phosphate groups bonded together to form the
sugar-phosphate backbone
