Biology Unit 1 Module 2 Flashcards
Module 2 Genetics
Draw and Label the Structure of DNA and RNA
What are nucleic acids?
Long thread-like molecules built up of monomers are called nucleotides. Nucleotides are joined together in a long chain.
What are the two nucleic acids?
DNA- deoxyribonucleic acid
RNA- ribonucleic acid
Where is DNA found and what is its function?
DNA can be found in the nucleus. It controls which enzymes and proteins are synthesized by cells
Where is RNA found?
RNA can be found (on the ribosomes) in the cytoplasm
Where else can nucleic acids be found?
The mitochondria and chloroplast
What are the characteristics a nucleic acid DNA must have? (5)
- Must be able to be replicated accurately. When the cell’s nucleus divides, it must pass on the exact gene copy of each molecule to the nucleus of its daughter cell.
- The molecule must be metabolically stable to prevent imperfect copies which could lead to an increased risk of mutation.
- Must be able to carry instruction and biological information.
- Must provide means of transferring information into cell characteristics.
- The amount of DNA remains constant for all cells within a species except gametes.
What are nucleotides?
Monomers of nucleic acids.
What are the components of a nucleotide?
A pentose sugar (ribose in RNA and deoxyribose in DNA), a nitrogenous base, and a phosphate group.
What is the importance of the phosphate group?
It is chemically reactive which allows new groups to be added by condensation reactions. The phosphate group gives the nucleic acids their acidic nature.
What is the makeup of a pentose sugar, its importance, and additionally what pentose sugar is used in DNA vs RNA?
This is a 5-carbon sugar which exists in a 5-sided ring form. It plays a role in the linkage of different nucleotides. The pentose sugar in DNA is deoxyribose and RNA is ribose.
What is the nitrogenous base characterized into?
PURINE: Adenine (A) and Guanine (G) double rings composed of a 6-sided ring and a 5-sided ring
PYRIMIDINE: Uracil (U), Cytosine (C), and Thymine (T). single rings each composed of 6 sides
How do we pair the bases in DNA?
GC, AT,
How do we pair the bases in RNA?
GC, AU
In which stage of the cell cycle does base paring occur and where?
It occurs during interphase in the cell’s nucleus.
What are the two types of linkages in Nucleic Acids?
- Phosphodiester Linkage
- Complementary Base-Pairing
What is a phosphodiester bond?
(What does it bond together, what is the base sequence, what type of bonding occurs and how does this bond physically impact the molecule)
This is a bond between the sugar group of one nucleotide and the phosphate group of another nucleotide. This bond occurs between the carbon 5 of one sugar and the carbon 3 of another sugar (base sequences 5’ to 3’). The type of bonding that occurs is covalent bonding. Finally, the bond determines the shape and the properties of the molecule produced.
What is complementary base pairing? (What is the linkage between, what type of bond makes the possible, what is the base pairing like, and what shape is formed?
This is the linkage between nucleotides and is facilitated by hydrogen bonds between the base pairs. The bases projecting from the sugar-phosphate backbone of parallel strands of nucleotides which run in opposite directions are held by hydrogen bonds. This bond forms a 3-D configuration that stabilizes the molecule.
What are the constraints of base pairing? (3)
The sugar-phosphate backbone of the two strands must run in opposite directions.
Base pairing normally occurs between particular pairs of bases.
One complete turn in the double helix strand is equal to 10 base pairs.
