Homeostasis and Biochemistry Review Flashcards

Flashcards covering key vocabulary from lectures on Homeostasis, Properties of Water, Organic and Inorganic Compounds, Acid-Base Chemistry, and Biomolecules (Carbohydrates, Lipids, Proteins, Nucleic Acids).

Homeostasis

The maintenance by an organism of a relatively stable internal environment.

Sensory receptor cells

Components of homeostatic control mechanisms that detect specific changes (stimuli) in the environment.

High heat capacity

A property of water meaning it takes a lot of energy to move its temperature up or down.

High heat of vaporization

A property of water meaning it takes 540 calories of heat energy to move 1g of water into vapor.

Solvent

A substance that dissolves other substances; water is a good example.

Hydrophilic molecules

Molecules that dissolve in water.

Cohesion

The property of water molecules sticking to each other.

Adhesion

The property of water molecules sticking to other surfaces.

Hydrogen bonding

A chemical bond where a hydrogen atom is attracted to a highly electronegative atom (like oxygen, nitrogen, or fluorine); a special type of dipole-dipole interaction.

Polarity of water molecules

Results from the unequal sharing of electrons between oxygen and hydrogen, allowing it to act as a solvent and form hydrogen bonds.

Hydrolysis Reaction

A reaction where water is added to take apart a complex molecule (opposite of dehydration synthesis).

Hydrophobic substances

Water-fearing substances (non-polar molecules like oils and fats) that repel water and tend to separate from it.

Hydrophilic substances

Water-loving substances (polar molecules or ionic compounds) that tend to mix, dissolve, or bond with water.

Organic compounds

Almost all carbon-containing compounds (naturally occurring or man-made) that contain carbon and hydrogen.

Inorganic compounds

Compounds that do not contain carbon, excluding CO2, carbonates, and all ionic salts.

Functional group

A particular cluster of atoms that always behaves in a certain way (e.g., -COOH).

Monomer

A simple organic molecule that exists individually.

Polymer

Two or more monomers put together.

Dehydration Synthesis (Synthesis Reactions)

A reaction where water is taken out to join two organic molecules together to make a polymer.

Acidic solutions

Solutions that produce high concentrations of H+ ions.

Basic solutions

Solutions that produce low concentrations of H+ ions.

pH Scale

A measurement of how acidic or basic a substance is, with 7 representing a neutral solution.

Buffers

Chemicals that keep the pH within normal limits by taking up excess H+ or OH- ions.

Positive Feedback

A mechanism that brings about rapid change because an activity or substance promotes another, amplifying the original stimulus.

Negative Feedback

A homeostatic mechanism that resists change by sensing a stimulus and activating processes that counteract it, reversing the direction of the response.

Polarity

The unequal sharing of electrons between atoms in a covalent bond, causing partial charges on the atoms.

Carbohydrates

Biomolecules used for quick energy and short-term storage, structural support in plants, and cell-to-cell recognition.

Monosaccharides

Simple sugars, the monomers of carbohydrates (e.g., glucose, pentose, hexose).

Disaccharides

Carbohydrates containing two monosaccharides joined during a dehydration reaction (e.g., sucrose, lactose).

Polysaccharides

Complex carbohydrates containing multiple glucose monomers (e.g., starch, glycogen, cellulose).

Starch

A branched chain of glucose molecules, serving as a storage form of glucose in plants.

Glycogen

A highly branched polymer of glucose, serving as the storage form of glucose in animals.

Cellulose

A polysaccharide found in plant cell walls that humans cannot digest, also known as dietary fiber or roughage.

Lipids

Biomolecules (fats and oils) that contain more energy per gram than other biological molecules.

Triglycerides

Fats and oils formed when one glycerol molecule reacts with three fatty acid molecules.

Fatty acid

A hydrocarbon chain that ends with the acidic group COOH.

Saturated fatty acid

A fatty acid with no double bonds between carbon atoms, typically solid at room temperature.

Unsaturated fatty acid

A fatty acid containing double bonds between carbon atoms, typically liquid at room temperature.

Phospholipids

Lipids constructed with a hydrophilic phosphate head and hydrophobic fatty acid tails, forming cellular membranes.

Amphipathic

Possessing both hydrophobic (water-fearing) and hydrophilic (water-loving) properties.

Steroids

Lipids containing a backbone of four fused carbon rings (e.g., cholesterol, testosterone, estrogen).

Proteins

Polymers with amino acid monomers, essential for virtually every structure and activity in the cell.

Amino Acid

The monomer of proteins, characterized by an amino group, a carboxylic acid group, and a unique side chain (R group).

Peptide bond

The bond that joins two amino acids together in a protein chain.

Primary structure (protein)

The linear sequence of amino acids joined by peptide bonds in a polypeptide chain.

Secondary structure (protein)

The regular folding patterns (like alpha helices or beta sheets) formed by hydrogen bonding between amino acids in a polypeptide.

Tertiary structure (protein)

The overall three-dimensional globular shape of a single polypeptide chain, formed by interactions between R groups.

Quaternary structure (protein)

The arrangement of multiple polypeptide chains when two or more join together to form a functional protein (e.g., hemoglobin).

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, a modified nucleotide with three phosphate groups.

Purines

Double-ring nitrogenous bases found in nucleic acids (Adenine, Guanine).

Pyrimidines

Single-ring nitrogenous bases found in nucleic acids (Cytosine, Uracil, Thymine).

DNA Bonding Rules

Adenine (A) always binds with Thymine (T), and Guanine (G) always binds with Cytosine (C).

Double Helix

The characteristic two-stranded, coiled structure of DNA, held together by hydrogen bonding between complementary base pairs.

Nucleic Acids

Biomolecules (DNA and RNA) that store and transmit genetic information and code for proteins.

DNA (Deoxyribonucleic acid)

The nucleic acid that stores all genetic information, made up of repeating nucleotide monomers.

Nucleotide

The monomer of DNA and RNA, consisting of a phosphate group, a pentose sugar, and a nitrogen-containing base.