ap bio unit 1

What is energy in living systems?

Energy is required for all biological processes like growth, reproduction, and maintaining organization; it is stored in chemical bonds.

What does the Law of Conservation of Energy state?

Energy cannot be created or destroyed, only transformed.

What is matter?

Matter is anything that has mass and occupies space.

What is an element?

An element is a basic substance that composes all matter (biotic and abiotic).

What is an atom?

An atom is the smallest unit of an element that retains its properties.

What are protons?

Protons are positively charged particles located in the nucleus.

What are neutrons?

Neutrons are neutral particles located in the nucleus.

What are electrons?

Electrons are negatively charged particles found in electron shells around the nucleus.

What is a molecule?

A molecule is two or more atoms bonded together.

What is an ion?

An ion is an atom that has gained or lost electrons, giving it a charge.

What is an ionic bond?

An ionic bond is formed by the transfer of electrons, resulting in attraction between oppositely charged ions; it is weak in water.

What is a covalent bond?

A covalent bond is formed by sharing electrons; it is strong and stable in biological systems.

What is water (H₂O)?

Water is a polar molecule with partial charges that forms hydrogen bonds.

What is adhesion?

Adhesion is the attraction between water and other substances.

What is cohesion?

Cohesion is the attraction between water molecules.

What is surface tension?

Surface tension is high cohesion at the surface creating a 'skin-like' effect.

What is capillary action?

Capillary action is the movement of water against gravity due to cohesion and adhesion.

What does 'high specific heat' mean?

High specific heat means water resists temperature change due to hydrogen bonding.

Why does ice float?

Ice floats because solid water is less dense than liquid due to an open hydrogen-bond structure.

What is a universal solvent?

Water is a universal solvent because it dissolves many substances, especially polar ones.

What is the dissociation of water?

The dissociation of water involves water splitting into H⁺ and OH⁻ ions.

What is pH?

pH is a measure of hydrogen ion concentration in a solution.

What is an acid?

An acid is a substance with high H⁺ concentration (pH < 7).

What is a base (alkaline)?

A base is a substance with low H⁺ concentration (pH > 7).

What is a buffer?

A buffer is a substance that stabilizes pH and maintains homeostasis.

What is a monomer?

A monomer is a small molecular subunit that builds polymers.

What is a polymer?

A polymer is a large molecule made of repeating monomers.

What is a functional group?

A functional group is a group of atoms attached to a carbon skeleton giving specific properties.

What is a hydroxyl group?

A hydroxyl group is a functional group represented as –OH.

What is a carbonyl group?

A carbonyl group is a functional group represented as –CO.

What is a carboxyl group?

A carboxyl group is a functional group represented as –COOH.

What is an amino group?

An amino group is a functional group represented as –NH₂.

What is a phosphate group?

A phosphate group is a functional group represented as –PO₄.

What is dehydration synthesis?

Dehydration synthesis is a process that joins monomers by removing water.

What is hydrolysis?

Hydrolysis is a process that breaks bonds by adding water.

What are carbohydrates?

Carbohydrates are macromolecules made of C, H, O used for short-term energy and structure.

What is a monosaccharide?

A monosaccharide is a simple sugar (e.g., glucose).

What is a polysaccharide?

A polysaccharide is a complex carbohydrate (e.g., starch, cellulose).

What is a glycosidic bond?

A glycosidic bond is a covalent bond linking sugars.

What are lipids?

Lipids are nonpolar molecules used for long-term energy storage and structure.

What is a saturated fat?

A saturated fat has no double bonds and is solid at room temperature.

What is an unsaturated fat?

An unsaturated fat has one or more double bonds and is liquid at room temperature.

What is a triglyceride?

A triglyceride is a lipid made of glycerol and 3 fatty acids used for energy storage.

What is a phospholipid?

A phospholipid is a lipid with a hydrophilic head and hydrophobic tails that forms cell membranes.

What is a steroid?

A steroid is a lipid based on cholesterol structure (e.g., hormones).

What is a protein?

A protein is a macromolecule made of amino acids that performs many cellular functions.

What is an amino acid?

An amino acid is a monomer of proteins with a variable R-group.

What is a peptide bond?

A peptide bond is a covalent bond between amino acids.

What is denaturation?

Denaturation is the loss of protein structure due to heat, pH, or chemicals.

What is the primary structure of a protein?

The primary structure is the sequence of amino acids in a protein.

What is the secondary structure of a protein?

The secondary structure consists of alpha helices and beta sheets stabilized by hydrogen bonds.

What is the tertiary structure of a protein?

The tertiary structure is the 3D folding of a protein based on R-group interactions.

What is the quaternary structure of a protein?

The quaternary structure is formed by multiple polypeptide chains assembling into a functional protein.

What are nucleic acids?

Nucleic acids are macromolecules that store genetic information.

What is a nucleotide?

A nucleotide is a monomer of nucleic acids consisting of a phosphate group, sugar, and base.

What is DNA?

DNA is a double-stranded nucleic acid that stores genetic information, composed of bases A, T, C, and G.

What is RNA?

RNA is a single-stranded nucleic acid involved in gene expression, composed of bases A, U, C, and G.

What does 'antiparallel' mean in the context of DNA?

Antiparallel refers to the arrangement of DNA strands running in opposite directions.

What is a phosphodiester bond?

A phosphodiester bond links nucleotides in a nucleic acid.

What are purines?

Purines are double-ring bases that include Adenine (A) and Guanine (G).

What are pyrimidines?

Pyrimidines are single-ring bases that include Cytosine (C), Thymine (T), and Uracil (U).

What is complementary base pairing?

In complementary base pairing, A pairs with T (or U), and C pairs with G.

What are hydrogen bonds in DNA?

Hydrogen bonds are weak bonds holding base pairs together in DNA, with A-T pairs having 2 bonds and C-G pairs having 3 bonds.