Biology Lecture Notes on Proteins and Nucleic Acids

Flashcards covering key concepts from the lecture notes on Proteins and Nucleic Acids, including their structure, function, and relationship to genetics and evolution.

What are proteins?

Long chains (polymers) of subunits called amino acids.

What are the characteristics of amino acids?

20 different types. Amino end, carboxyl end, R group, and Hydrogen atom. Joined by peptide bonds, which are produced by dehydration synthesis reactions.

What are the functions of proteins?

Structural support, enzymes, defense, transport, motion, regulation, and storage.

What determines protein structure and function?

The sequence of amino acids determines a protein's shape/structure, and the protein's shape determines its function.

What can cause a protein to unravel and lose its shape (denaturation)?

Unfavorable temperature and pH changes.

What are the four levels of protein structure organization?

Primary, secondary, tertiary, and quaternary.

What is the primary structure of a protein?

Amino acid sequence.

What is the secondary structure of a protein?

Coils and folds in the polypeptide chain, such as alpha helixes and beta pleated sheets, stabilized by hydrogen bonding.

What determines the tertiary structure of a protein?

Interactions among various side chains (R Groups).

What is the quaternary structure of a protein?

Interaction of two or more polypeptide chains, often involving disulfide bonding.

What determines a protein's function?

A protein's specific shape determines its function.

What are enzymes?

Biological catalysts that speed up chemical reactions without being altered or consumed.

What is denaturation of proteins?

Alterations in pH, salt concentration, or temperature that cause a protein to unravel and become biologically inactive.

What is sickle cell disease?

A inherited blood disorder resulting from a single amino acid substitution in the hemoglobin protein.

What are nucleic acids?

Long chains containing subunits known as nucleotides.

What are the three parts of a nucleotide?

Phosphate group, 5-carbon sugar, and nitrogenous base.

What are the two kinds of nucleic acids?

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

What are the functions of nucleic acids?

Store genetic information and provide information to be used to make proteins.

What are nucleosides?

Nitrogenous base + sugar.

What are the pyrimidines?

Cytosine, thymine, and uracil.

What are the purines?

Adenine and guanine.

What is the structure and composition of DNA?

Double-stranded, contains deoxyribose sugar, and uses the nitrogenous bases adenine, guanine, cytosine, and thymine.

What are the base pairing rules in DNA?

Adenine pairs with thymine (A:T), and cytosine pairs with guanine (C:G).

What is the structure and composition of RNA?

Single-stranded, contains ribose sugar, and uses the nitrogenous bases adenine, guanine, cytosine, and uracil.

What are the functions of DNA and RNA in protein synthesis?

DNA provides instructions for making RNA, and RNA provides instructions for making proteins.

What is the central dogma of molecular biology?

DNA → RNA → Proteins.

What is adenosine triphosphate (ATP)?

Nucleotide containing adenosine and triphosphate groups; the energy currency of the cell.

How does ATP provide energy for the cell?

The breakdown (hydrolysis) of ATP yields energy for the cell. The reaction is reversible.

How are DNA and proteins used in the study of evolution?

DNA and protein sequences can be used to establish evolutionary relationships between organisms.