Biology Nucleic Acid Key terms + Practice Questions

DNA (Deoxyribosenucleic acid)

codes for the genome of the cell (entire genetic continent, thousands of genes), which contain instruction for producing proteins or various forms of RNA, and also controls all cellular activities by turning genes on or off.

Structure of DNA

Exhibits a double helix structure, where the sugar and phosphate lie on outside of helix, and nitrogenous are are stack in interior. Strands of helix run in opposite directions (antiperralllel orientation). In antiparallel orientation, complementary base pairing means one strand runs 5’ to 3’ and the other runs 3’ to 5’. Adenine forms hydrogen bonds (base pairs) with thymine, guanine base pairs with cytosine.

RNA (Ribonucleic Acid)

often single stranded, Complementary pairing can also occur between two RNA molecules or between parts of the same molecule. In RNA, thymine (T) is replaced by uracil (U), so A and U pair. While DNA always exists as a double helix, RNA molecules are more variable in form

nucleotides (the monomer)

DNA and RNA consist of this monomer, which contains three parts: Nitrogenous base, pentose sugar, and one or more phosphate groups.

Types of Nitrogenous bases

Pyramides (One ring) - Cytosine (C), thymine (T), uracil (U). Purines (Two rings) - adenine (A) and guanine (G)

Types Of Pentose sugars

Deoxyribose (found in DNA) Ribsone (found in RNA)

Pyramides (CTU 1 ring)

Cytosine (C), thymine (T), uracil (U). Only have one ring

Purines (AG 2 rings)

Consist of two rings, and contain adenine (A) and guanine (G)

ATP

Adenosine triphosphate, energy currency of the cell. Cells use energy released by breaking down food molecules to synthesize ATP.

complementary base pairing concept

(purine with pyramid), In antiparallel orientation, complementary base pairing means one strand runs 5’ to 3’ and the other runs 3’ to 5’. Adenine (A) forms hydrogen bonds (base pairs) with thymine (T) [A→T] , guanine (G) base pairs with cytosine (C) [G→C] . In RNA, (A)denine base pairs with uracil (U) instead of thymine (T) [A→U]

Chromatin

complex of DNA and histone proteins

Chromosomes

threadlike structures of the DNA containing tightly wound and packed chromatin around nucleosomes

QUIZ: Nucleic Acids… (Choose what applies)

Contans a sugar

Contains an R group

can be used as an energy source

are the building blocks for polypeptides

Contains a sugar, can be used as an energy source

QUIZ: Which is the correct match of nucleotides (and #) hydrogen bonds

G/C (3 hydrogen bonds)

HW: DNA and RNA… (Select all that are true)

both form a double helix

are both commonly double stranded in human cells

contain different sugars

both contain the nucleotides: adenine (A) guanine (G) and cytosine (C)

contain different sugars, both contain the nucleotides: adenine (A) guanine (G) and cytosine (C)

HW: Pick which of these combinations falls under the nucleic acid biomolecule

Carbon, hydrogen, oxygen

Carbon, hydrogen, oxygen, nitrogen, phosphorus

Carbon, hydrogen, oxygen, nitrogen (sometimes sulfur)

Sugar, phosphate, nitrogenous base

Carbon, hydrogen, oxygen, nitrogen, phosphorus/// sugar, phosphate, nitrogenous base