AP Bio Chapter 1 Stuff I needed better flashcards for :)

Organic Phosphate

A functional group with a phosphorus atom bonded to four oxygen atoms, often carrying a negative charge, important for storing and transferring energy in molecules like ATP and DNA.

Thiol

A functional group containing a sulfur atom bonded to a hydrogen atom, capable of forming strong disulfide bonds that stabilize protein structures.

Carboxylic Acid

A group consisting of a carbon atom double-bonded to an oxygen and also bonded to a hydroxyl group, acts as an acid by donating hydrogen ions.

Amino Group

A group with a nitrogen atom bonded to two hydrogens, acts as a base by accepting hydrogen ions, and is a key part of building blocks of proteins.

Alcohol

A hydroxyl group composed of an oxygen bonded to a hydrogen, makes molecules polar and able to interact with water.

Aldehyde

A group where a carbon atom is double-bonded to an oxygen and also bonded to a hydrogen, commonly found in sugars and involved in chemical reactions.

Phosphate

Negative/Acidic

Carboxyl

Negative/Acidic

Amino

Positive/Basic

Structural Isomer

Molecules that have the same chemical formula but differ in how their atoms are connected to each other.

Enantiomer

Molecules that are mirror images of each other around a chiral center and cannot be superimposed; only one may be biologically active.

Epimer

Molecules that differ in the configuration at a single carbon atom, but are not mirror images.

Anomer

Molecules that differ in the orientation of a hydroxyl group around the carbon formed when a sugar cyclizes into a ring.

Cis Isomer (Geometric)

Molecules with substituents on the same side of a double bond, introducing a bend or kink in the chain that affects fluidity.

Trans Isomer (Geometric)

Molecules with substituents on opposite sides of a double bond, creating a straighter chain that can pack more tightly and have a higher melting point.

Positional Isomer

Molecules that have the same functional groups and formula but the functional group is attached to a different carbon atom, resulting in different biological roles.

Primary Structure

Linear sequence of amino acids linked by peptide bonds; determines all higher levels of protein folding.

Secondary Structure

Local folding of the polypeptide into α-helices or β-pleated sheets, stabilized by hydrogen bonds between backbone atoms.

Tertiary Structure

Three-dimensional folding of a single polypeptide chain stabilized by hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges between R-groups.

Quaternary Structure

Arrangement and interaction of multiple polypeptide chains, held together by hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges between R-groups.

Peptide Bond

Covalent bond linking the carboxyl group of one amino acid to the amine group of another, formed during a condensation reaction.

R-group (Side Chain)

Variable part of an amino acid that determines its chemical properties, such as polarity, charge, or ability to form bonds.

Hydrogen Bond

Non-covalent interaction between a hydrogen attached to a polar atom and another electronegative atom; stabilizes secondary and tertiary structures.

Ionic Bond

Attraction between positively and negatively charged R-groups; contributes to tertiary and quaternary structure.

Disulfide Bridge

Covalent bond formed between sulfur atoms of two cysteine amino acids; stabilizes tertiary or quaternary structure.

Hydrophobic Interaction

Nonpolar R-groups cluster away from water, helping stabilize tertiary and quaternary structures.

Denaturation

Disruption of a protein's shape caused by heat, pH changes, or chemicals, breaking hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.

Cysteine

A sulfur-containing amino acid that can form disulfide bridges to stabilize protein structure.

Serine

Polar amino acid with a hydroxyl group, capable of forming hydrogen bonds in secondary and tertiary structure.

Asparagine

Polar amino acid with an amide group, capable of forming hydrogen bonds and contributing to tertiary and quaternary interactions.

Phenylalanine

Nonpolar, hydrophobic amino acid that participates in hydrophobic interactions in protein folding.

Alpha-Helix

Secondary protein structure shaped like a coiled spring, stabilized by hydrogen bonds between backbone atoms.

Beta-Pleated Sheet

Secondary protein structure formed by laterally aligned polypeptide chains, stabilized by hydrogen bonds between backbone atoms.

Condensation Reaction

Chemical reaction in which two amino acids are joined by a peptide bond, releasing a molecule of water.

Functional Group

Specific group of atoms within a molecule that determines its chemical properties and reactivity.

pentose sugar

1/3 monomers used to make nucleic acids

Purines

G and A

Pyrimadines

C and T and U

Purines (Length)

5 to 6 Longer

Pyrimidines (Length)

just 6 Shorter

Tertiary and Secondary

Lost when a single polypeptide is denatured

Glucose

Main source of energy for cells; used in cellular respiration to produce ATP.

Triglycerides

Long-term energy storage, insulation, and cushioning of organs.

Phospholipids

Form cell membranes; create a hydrophobic barrier with hydrophilic heads facing outward.

Steroids

Act as signaling molecules (hormones), stabilize cell membranes.

Starch

Plant storage polysaccharide; energy storage in plants.

Cellulose

Structural component in plant cell walls; provides rigidity and support.

Chitin

Structural polysaccharide in fungal cell walls and exoskeletons of arthropods.

Cholesterol

Stabilizes cell membrane fluidity; precursor for steroid hormones.

Proteins

Perform a wide variety of functions including catalysis (enzymes), structural support, transport, signaling, defense (antibodies), and movement.