SCIC Ch 3 exam

What is a protein?

A biological macromolecule composed of one or more long chains of amino acids.

What is an $\alpha$-helix?

A common secondary structure of proteins where the amino acid chain is coiled into a spiral.

What is a $\beta$-sheet?

A secondary structure where segments of the protein chain line up side-by-side, held together by hydrogen bonds.

What is an essential amino acid?

An amino acid that cannot be synthesized by the body and must be obtained through diet.

What is a complete protein?

A food source that contains all nine essential amino acids in sufficient amounts.

What is an active site?

The specific region of an enzyme where substrate molecules bind and undergo a chemical reaction.

What is the primary structure of a protein?

The unique, linear sequence of amino acids in a protein chain.

What is secondary structure in proteins?

Local folding patterns within a protein, such as $\alpha$-helices or $\beta$-sheets.

What is tertiary structure?

The overall three-dimensional shape of a single protein molecule.

What is denaturation?

The process in which a protein loses its native shape and function due to external stress like heat or acid.

What is DNA?

The molecule that carries genetic instructions for the development and functioning of living organisms.

What is a nucleotide?

The basic building block of DNA and RNA, consisting of a sugar, a phosphate group, and a nitrogenous base.

What are the nitrogenous bases of DNA?

Adenine (A), Thymine (T), Guanine (G), and Cytosine (C); they form the 'rungs' of the DNA ladder.

What is gene expression?

The process by which information from a gene is used to synthesize a functional gene product, usually a protein.

What is transcription?

The process of copying a segment of DNA into RNA.

What is translation?

The process where ribosomes create proteins based on the instructions carried by mRNA.

What does complementarity refer to in DNA?

The relationship between two structures following the lock-and-key principle, specifically how A pairs with T and G pairs with C.

What is a base pair?

Two complementary nitrogenous bases held together by hydrogen bonds.

What is a gene?

A specific sequence of DNA that encodes the instructions for a single protein or trait.

What is a codon?

A sequence of three nucleotides that corresponds to a specific amino acid.

What is an intron?

A non-coding sequence of DNA within a gene that is removed during RNA processing.

What is an exon?

A coding sequence of DNA that remains in the final mRNA and is expressed as a protein.

What is a virus?

A small infectious agent that replicates only inside the living cells of an organism.

What is a mutation?

A permanent alteration in the DNA sequence of a gene.

What is cloning?

The process of producing genetically identical copies of a biological entity.

What is polymerase chain reaction (PCR)?

A laboratory technique used to rapidly make millions of copies of a specific DNA sample.

What is recombinant DNA?

DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources.

What are genetically modified foods?

Foods derived from organisms whose genetic material has been altered using genetic engineering.

What is a double blind trial?

A medical study where neither the participants nor the researchers know who is receiving a particular treatment to prevent bias.

What is COX-1?

An enzyme that helps maintain the stomach lining and kidney function.

What is COX-2?

An enzyme primarily responsible for inflammation and pain.

What is a solute?

The substance that is dissolved in a solution.

What is a solvent?

The substance (usually a liquid) in which the solute dissolves.

What is a solution?

A homogeneous mixture of two or more substances.

What does solubility refer to?

The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature.

What is a saturated solution?

A solution containing the maximum concentration of a solute.

What is an electrolyte?

A substance that produces an electrically conducting solution when dissolved in water.

What is an acid?

A substance that increases the $H^+$ (hydrogen ion) concentration of a solution.

What is a base?

A substance that increases the $OH^-$ (hydroxide ion) concentration or accepts $H^+$.

What is the difference between strong and weak acids/bases?

Strong acids/bases ionize completely in water; weak ones only partially ionize.

What is an indicator?

A substance that changes color in response to a chemical change, such as pH.

What is a buffer?

A solution that resists changes in pH when small amounts of an acid or a base are added.

What is oxidation?

The loss of electrons during a reaction.

What is reduction?

The gain of electrons during a reaction.

What is a redox reaction?

A chemical reaction involving the transfer of electrons between two species.

What is a half-reaction?

Either the oxidation or reduction component of a redox reaction.

What is an oxidizing agent?

The substance that gains electrons and is reduced.

What is a reducing agent?

The substance that loses electrons and is oxidized.

What is an anode?

The electrode where oxidation occurs.

What is a cathode?

The electrode where reduction occurs.

What is a primary battery?

A non-rechargeable battery designed to be used once and discarded.

What is a secondary battery?

A rechargeable battery that can be used multiple times.

What is a fuel cell?

An electrochemical cell that converts chemical energy from a fuel (like hydrogen) into electricity through a reaction with oxygen.

What is a carbon economy?

An economy based on the use of fossil fuels and carbon-based energy.

What is a hydrogen economy?

A proposed system of delivering energy using hydrogen as a low-carbon fuel source.