Nucleic Acids and Lipids Lecture Review

Flashcards covering types of nucleic acids, central dogma, DNA/RNA/protein synthesis, nucleotide structure, DNA and RNA polynucleotide structure, lipids definition, types, structure of fats, phospholipids, and steroids.

What is the primary function of DNA?

To store genetic information.

What is the primary role of RNA in the cell?

It is involved in protein synthesis and regulation.

What is the Central Dogma of Molecular Biology?

It describes the flow of genetic information from DNA transcription into RNA and translation into protein.

What is the sequence of information flow according to the Central Dogma of Molecular Biology?

DNA
RNA
Protein.

What is DNA Replication?

It is the copying of DNA before cell division.

What is Transcription?

It is the synthesis of RNA from a DNA template.

What is Translation?

It is protein synthesis using an mRNA template at the ribosome.

What are the three main components that make up a nucleotide?

A nitrogenous base, a pentose sugar, and one or more phosphate groups.

What are the two types of nitrogenous bases found in nucleic acids?

Purines (Adenine, Guanine) and Pyrimidines (Cytosine, Thymine, Uracil).

Which pentose sugar is found in DNA?

Deoxyribose.

Which pentose sugar is found in RNA?

Ribose.

Which pyrimidine base is unique to DNA?

Thymine.

Which pyrimidine base is unique to RNA?

Uracil.

Describe the general structure of DNA.

It is a double-stranded helix with antiparallel strands, where bases pair A with T, and G with C.

Describe the general structure of RNA.

It is single-stranded and can fold into secondary structures. It contains Uracil instead of Thymine.

What are lipids?

They are a diverse group of hydrophobic or amphipathic molecules mainly composed of hydrocarbons, insoluble in water but soluble in organic solvents.

Name the three main types of lipids.

Fats (Triglycerides), Phospholipids, and Steroids.

What are fats (triglycerides) composed of?

A glycerol backbone and three fatty acid chains.

Describe the basic structure of a fatty acid.

It is a long hydrocarbon chain with a carboxyl group.

What are phospholipids composed of?

Glycerol, two fatty acids (hydrophobic tails), and a phosphate group with a polar head (hydrophilic).

What is the primary function of phospholipids in cell membranes?

They form bilayers that are critical for membrane structure and function.

Which part of a phospholipid is hydrophobic?

The two fatty acid tails.

Which part of a phospholipid is hydrophilic?

The phosphate group with a polar head.

What is the characteristic structure of steroids?

They are lipids with four fused carbon rings.

What is one key function of cholesterol regarding cell membranes?

It modulates membrane fluidity.

Besides modulating membrane fluidity, what is cholesterol a precursor for?

Steroid hormones (e.g., testosterone, estrogen), bile acids, and vitamin D.