Biological Molecules

Unit 1- Final Exam Prep

Biomolecule

Chemical compounds found in living organisms.

Monomer

Small units that bond to form larger chains.

Polymer

Larger molecules made of bonded monomers.

Dehydration Synthesis

Reaction forming bonds by removing water.

Hydrolysis

Reaction breaking bonds by adding water.

Amino Acid

Building blocks of proteins with side chains.

Peptide Bond

Covalent bond linking amino acids.

Carboxyl Group

Functional group acting as an acid.

Hydroxyl Group

Functional group containing -OH, acts as alcohol.

Carbonyl Group

Functional group with C=O structure.

Amino Group

Functional group containing -NH₂, acts as base.

Phosphate Group

Functional group with -PO₄, involved in energy transfer.

Sulfhydryl Group

Functional group with -SH, forms disulfide bonds.

Methyl Group

Functional group with -CH₃, affects gene expression.

Carbohydrates

Sugars and polymers serving as energy sources.

Monosaccharides

Single sugar units like glucose and fructose.

Disaccharides

Two sugar units linked together, e.g., sucrose.

Polysaccharides

Long chains of monosaccharides, e.g., starch.

Glycosidic Linkage

Bond between two monosaccharides in carbohydrates.

Isomers

Compounds with the same formula but different structures.

Hydrocarbon

Compounds containing only hydrogen and carbon.

Hydrolysis Reaction

Breakdown of compounds using water.

Structural Formula

Representation showing the arrangement of atoms.

Glucose

A simple sugar, primary energy source.

Fructose

A sugar found in many plants, fruit.

Glycolipid

Lipid with carbohydrate attached, cell membrane component.

Glycoprotein

Protein with carbohydrate attached, involved in cell recognition.

Starch

Polysaccharide used for energy storage in plants.

Fats

Energy-rich lipids, composed of glycerol and fatty acids.

Phospholipids

Lipids with hydrophilic head and hydrophobic tails.

Saturated Fats

Fats with no double bonds in fatty acids.

Unsaturated Fats

Fats with one or more double bonds in fatty acids.

Triglycerides

Fats formed from glycerol and three fatty acids.

Cholesterol

Steroid important for cell membrane structure.

Steroids

Lipids with four fused carbon rings structure.

Amphipathic

Molecule with both hydrophilic and hydrophobic regions.

Proteins

Polymers made of amino acids, perform various functions.

Amino Acids

Building blocks of proteins, 20 types exist.

Peptide Bonds

Covalent bonds linking amino acids in proteins.

Dipeptide

Two amino acids linked by a peptide bond.

Polypeptide

Chain of amino acids, forms proteins.

Primary Structure

Sequence of amino acids in a polypeptide.

Secondary Structure

Coiling or folding of polypeptide chains.

Tertiary Structure

Overall 3D shape of a polypeptide.

Quaternary Structure

Complex of multiple polypeptide chains.

Enzymes

Proteins that catalyze biochemical reactions.

Hormones

Chemical signals that regulate physiological processes.

Disulfide Bonds

Covalent bonds between cysteine amino acids.

Hydrogen Bonds

Attractive forces between polar R groups.

Hydrophobic Interactions

Non-polar amino acids cluster away from water.

Subunit

Individual polypeptide chain in a protein.

Denaturation

Loss of protein's 3D structure, non-functional.

Causes of Denaturation

Changes in pH, temperature, or heavy metals.

Nucleic Acids

Molecules that transmit hereditary information.

Nucleotide

Building block of nucleic acids, consists of three parts.

Five Carbon Sugar

Component of nucleotides; ribose or deoxyribose.

Nitrogenous Base

A, T, C, G in DNA; A, U, C, G in RNA.

DNA

Double-stranded nucleic acid, genetic material.

Double Helix

Twisted structure of DNA formed by base pairs.

Base Pairing

A pairs with T; C pairs with G.

RNA

Single-stranded nucleic acid, involved in protein synthesis.

mRNA

Messenger RNA, carries genetic information to ribosomes.

tRNA

Transfer RNA, brings amino acids to ribosomes.

ATP

Energy carrier molecule with three phosphate groups.

Polymers

Long chains of repeating monomer units.

Ionic Bonds

Electrons are transferred between atoms.

Cation

Positively charged ion, loses electrons.

Anion

Negatively charged ion, gains electrons.

Acids

Substances that release H+ ions in solution.

Bases

Substances that release OH- ions in solution.

pH Scale

Measures acidity or basicity of a solution.

Neutral pH

pH of 7, equal H+ and OH- concentrations.

Acidic Solution

pH less than 7, more H+ than OH-.

Basic Solution

pH greater than 7, more OH- than H+.

Buffers

Compounds that stabilize pH by neutralizing acids/bases.

Water Properties

Excellent solvent due to polar covalent bonds.

Cohesion

Attraction between like molecules, e.g., water.

Adhesion

Attraction between different substances, e.g., water and glass.

Surface Tension

Resistance of liquid surface to external force.

Universal Solvent

Water dissolves many substances due to polarity.

Hydrophilic

Substances that dissolve in water easily.

Hydrophobic

Substances that do not dissolve in water.

Electronegativity

Tendency of an atom to attract electrons.

Polar Covalent Bond

Unequal sharing of electrons between atoms.

Hydrogen Bonding

Weak bonds formed between hydrogen and electronegative atoms.

pH Change

Each unit change represents a tenfold change in H+ concentration.

Common Buffers

Bicarbonate and phosphate maintain pH in living organisms.

Buffer

Compound that stabilizes pH by H+ ion exchange.

Bicarbonate

Common buffer, maintains blood pH levels.

Phosphate

Buffer that helps regulate cellular pH.

Hydrogen Bond

Weak attraction between water molecules.

Calorie

Energy needed to raise 1g of water by 1°C.

Condensation

Gas turning into liquid, releasing heat.

Evaporation

Liquid turning into gas, absorbing heat.

Density of Ice

Ice floats due to lower density than water.

Heat Absorption

Water's ability to absorb heat without temperature change.

Polarity of Water

Unequal sharing of electrons creates a dipole.

Chemical Reactions

Processes facilitated by water's solvent properties.

Water Boatmen

Insects that utilize surface tension to float.

Aquatic Life Impact

Ice density change would harm aquatic ecosystems.