Nucleic Acids/Nucleotides (Part 1) Flashcards
What elements do nucleic acids contain?
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorous
Nucleic acids are polymers. What are their monomers?
Nucleotides.
What is the nucleotide made from?
- Pentose sugar (sugar containing 5 carbon atoms)
- Nitrogenous (nitrogen containing) base
- Phosphate group
What type of molecule is the phosphate group?
PO4(3-) is an inorganic molecule that is acidic and negatively charged.
What type of molecule is a nitrogenous base?
A complec organic molecule contatining one or two carbon rings, in its structure as well as nitrogen.
What does the nucleotide look like?
Nucleotide.
What does DNA stand for?
Deoxyribonucleic acid
What does RNA stand for?
Ribonucleic acid
What reaction links nucleotides together to form a polynucleotide?
Nucleotides are linked by condensation reactions.
What is the name of the polymer formed by linked nucleotides?
The polymer is called a polynucleotide.
Which two groups of adjacent nucleotides are involved in bond formation?
The phosphate group at the 5’ carbon of one nucleotide and the hydroxyl (OH) group at the 3’ carbon of the pentose sugar of the next nucleotide.
What type of bond is formed between adjacent nucleotides?
A phosphodiester bond.
Where specifically does the phosphodiester bond form?
Between the 5’ carbon of the phosphate group and the 3’ carbon of the sugar.
What is the structure of a polynucleotide?
A polynucleotide has a sugar-phosphate backbone with bases attached to each sugar.
How are phosphodiester bonds broken?
Phosphodiester bonds are broken by hydrolysis, which is the reverse of the condensation reaction, releasing individual nucleotides.
What is the sugar in DNA called, and how is it different from ribose?
The sugar in DNA is called deoxyribose, which has one fewer oxygen atom than ribose.
How many types of nucleotides are there in DNA?
There are four types of DNA nucleotides, each with a different base.
What are the two groups of DNA bases?
Pyrimidines (smaller bases with single carbon ring structures): Thymine (T) and Cytosine (C).
Purines (larger bases with double carbon ring structures): Adenine (A) and Guanine (G).
What is the structure of purines?
Double ringed
What is the structure of pyrimidines?
Single ringed
Which bases are purines?
Adenine and guanine
Which bases are pyrimidines?
Cytosine, thymine, and uracil
How do DNA bases pair, and what bonds form between them?
Thymine (T) pairs with Adenine (A) via two hydrogen bonds.
Cytosine (C) pairs with Guanine (G) via three hydrogen bonds.
Purines always pair with pyrimidines.
What type of bonds hold bases together?
Hydrogen bonds
Name the 5 nitrogenous bases
thymine
guanine
adenine
cytosine
uracil
Name the 4 bases present in DNA
thymine
adenine
guanine
cytosine
Name the 4 bases present in RNA
uracil
adenine
guanine
cytosine
Which base is never found in DNA?
Uracil
Which base is never found in RNA?
Thymine
In order to allow for the bases to form hydrogen bonds what must happen to one of the polynucleotide chains?
It must be rotated through 180 degrees
What is the structural shape of a DNA molecule?
DNA consists of two strands of polynucleotides coiled into a helix, known as the DNA double helix.
How long can a DNA molecule be?
DNA molecules can range in length from a few nucleotides to millions of nucleotides.
What holds the two strands of the double helix together?
The two strands are held together by hydrogen bonds between complementary bases, similar to the rungs of a ladder.
What is meant by DNA strands being “antiparallel”?
The two strands run in opposite directions, with one strand having a phosphate group (5’) at one end and a hydroxyl group (3’) at the other.
Why is the base pairing in DNA important?
The base pairing allows DNA to be copied and transcribed, which are essential properties for its role as the molecule of heredity.
What shape is the deoxyribose sugar?
Page 70 on the kerboodle textbook.
What shape is the phosphate group?
Page 70 on the kerboodle textbook.
What shape is the Adenine base?
Page 70 on the kerboodle textbook.
What shape is the Thymine base?
Page 70 on the kerboodle textbook.
What shape is the Cytosine base?
Page 70 on the kerboodle textbook.
What shape is the Guanine base?
Page 70 on the kerboodle textbook.
DNA Nucleotide diagram
DNA Nucleotide
RNA Nucleotide Diagram
RNA Nucleotide
What is complementary base pairing in DNA?
Adenine (A) pairs with Thymine (T) via two hydrogen bonds.
Cytosine (C) pairs with Guanine (G) via three hydrogen bonds.
Why does a pyrimidine always pair with a purine?
A small pyrimidine base pairs with a larger purine base to maintain a constant distance between the DNA backbones, ensuring parallel polynucleotide chains.
Who discovered the detailed structure of DNA and when?
The detailed structure of DNA was determined by Watson and Crick in 1953.
What does the sequence of bases along a DNA strand represent?
The sequence of bases carries the genetic information of an organism in the form of a code.
What is the primary role of RNA?
RNA plays an essential role in transferring genetic information from DNA to the proteins that make up enzymes and tissues.
Why can’t DNA directly supply genetic information for protein synthesis?
DNA is a very long molecule that cannot leave the nucleus due to its size and structure.
How is genetic information transferred from DNA to the protein synthesis site?
A short section of DNA corresponding to a single gene is transcribed into a shorter molecule called messenger RNA (mRNA).
How does the length of mRNA compare to DNA?
Each mRNA molecule is much shorter than the entire DNA chromosome, corresponding only to a single gene.
How are RNA nucleotides different from DNA nucleotides?
RNA contains the sugar ribose, while DNA contains deoxyribose.
RNA has the base uracil (U) instead of thymine (T). Uracil forms two hydrogen bonds with adenine (A).
Do base pairing rules still apply in RNA?
Yes, RNA nucleotides pair with DNA during transcription, following base pairing rules:
Adenine (A) pairs with Uracil (U).
Cytosine (C) pairs with Guanine (G).
How do RNA polymers form?
RNA nucleotides form polymers through the creation of phosphodiester bonds in condensation reactions, similar to DNA.
Why is RNA able to leave the nucleus?
RNA polymers are small enough to pass through the nuclear membrane and travel to ribosomes.
What happens to RNA after protein synthesis?
RNA molecules are degraded in the cytoplasm, the phosphodiester bonds are hydrolyzed, and the nucleotides are released and reused.
