Organic Compounds & Macromolecules Quizlet
Click each term to reveal the definition
What are inorganic compounds?
Molecules that contain C, H, or neither. Examples: O2, H2O, CO2, NaCl.
What are organic compounds?
Molecules that contain both C and H. Examples: C6H12O6, CH4.
Why is carbon important to organic compounds?
Carbon has 4 valence electrons and can form up to 4 covalent bonds (single, double, triple) with other elements, storing chemical energy. It bonds with other C atoms to form chain-like, ring-shaped, or branched macromolecules.
What are macromolecules?
Large molecules in living cells.
What is a monomer?
A single, smaller molecule that can react with other monomers to form polymers.
What is a polymer?
Many monomers bonded together, forming a macromolecule.
What are the four classes of organic compounds?
Carbohydrates, Lipids, Proteins and Amino Acids, Nucleic Acids.
What are carbohydrates? (description and role)
Organic molecules made up of atoms of carbon, hydrogen, and oxygen; energy source for metabolism.
Typical dietary sources of carbohydrates?
Sugar, starch, cellulose, glucose; rice, grains, potatoes, fruits.
What are lipids? (description and role)
Compounds composed of many carbon, hydrogen, and oxygen atoms; storage of unused chemical energy.
Typical dietary sources of lipids?
Fats, oils, and waxes; vegetable oils, nut oils, some dairy products.
What are proteins? (description and role)
Organic compounds made up of amino acids (each has unique number, combination, and arrangement); functions include growth and repair, as well as a source of energy.
Typical dietary sources of proteins?
Enzymes; meat, eggs, dairy products, legumes, nuts.
What are nucleic acids? (description and role)
Large complicated molecules that play a major role in heredity and in controlling the cell’s activities.
Examples of nucleic acids?
DNA (deoxyribonucleic acid), RNA (ribonucleic acid).
Elements in carbohydrates?
C, H, O
Monomer of carbohydrates?
Monosaccharide
Function of carbohydrates?
Energy source
What do carbohydrate names often end in?
-ose (means sugar)
What are monosaccharides?
Monomers of carbohydrates – “simple sugar”. Examples: Glucose, fructose, galactose. Molecular formula: C6H12O6.
What is dehydration synthesis?
Removal of water to bond monomers together to form polymers. One less water is removed than the number of monomers bonded together.
What is hydrolysis?
Water is added to break large polymers into monomers.
What are disaccharides?
2 monosaccharides bonded together. Examples: Sucrose, maltose, lactose. Molecular formula: C12H22O11 (water removed to form the bond).
What are polysaccharides?
“Complex carbohydrates” – macromolecules formed by many (hundreds to thousands) monosaccharides bonded together.
Examples of polysaccharides?
Cellulose (major plant cell wall component), Starch (energy/glucose storage in plants), Glycogen (energy/glucose storage in animal liver cells).
Elements in nucleic acids?
C, H, O, N, P
Monomer of nucleic acids?
Nucleotide
Function of nucleic acids?
Store and transmit hereditary information.
What is a nucleotide composed of?
Deoxyribose/ribose sugar, phosphate group, nitrogenous base.
DNA structure?
Double-stranded helix; bases: A-T, G-C pairs via hydrogen bonds.
RNA structure?
Single-stranded; bases: A-U, G-C.
Elements in lipids (fats)?
C, H, O
Molecular building blocks of lipids?
1 Glycerol and 3 Fatty Acids
Function of lipids?
Energy storage and component of cell membranes.
What is glycerol?
C3H8O3 (same in all lipids).
What are fatty acids?
Very long hydrocarbon (C-H) chains (nonpolar and hydrophobic); can be saturated/unsaturated.
What is a saturated fatty acid?
Hydrocarbon chain saturated with as many H’s as possible (no C=C bonds); straight, does not bend; solid at room temp (e.g., fats).
What is an unsaturated fatty acid?
Hydrocarbon chain has double bond(s) (C=C), allowing bending/kinking; liquid at room temp (e.g., oils).
What are triglycerides?
Fats and oils formed by dehydration synthesis (glycerol + 3 fatty acids – 3 H2O).
How does hydrolysis of a lipid work?
Adds 3 H2O (via lipase enzyme) to break into glycerol + fatty acids.
What are phospholipids?
Component of cell membranes; form a lipid bilayer. Made of phosphate group, 1 glycerol, 2 fatty acids. Heads: hydrophilic (polar); Tails: hydrophobic (nonpolar).
How does a phospholipid bilayer form?
Heads face water (inside/outside cell), tails face inward (away from water).
What are waxes?
Lipid-like molecules with diverse functions: form cuticle on leaves (decreases water loss), skin/fur maintenance, ear wax, beeswax for honeycombs.
Elements in proteins (polypeptides)?
C, H, O, N
Monomer of proteins?
Amino acids
Function of proteins?
Aids in metabolism – all of the dehydration synthesis and hydrolysis reactions in the body.
How are amino acids linked?
By peptide bonds (formed via dehydration synthesis).
How many types of amino acids?
20 types, differing in their R groups (side chains).
Where do amino acids come from?
Some must be consumed in diet (essential); others synthesized by body.
What makes each protein unique?
Types of amino acids, length of chain, order of amino acids; determines shape and function.
Specific protein examples: Contractile?
Aid in muscle contraction.
Specific protein examples: Structural support?
Aid in bone formation, hair, nails, collagen.
Specific protein examples: Hormones?
Chemical messengers that influence metabolism.
Specific protein examples: Pigments?
Colored proteins with essential roles, e.g., hemoglobin (red, transports O2 in blood).
Specific protein examples: Antibodies?
Detect antigens by shape and aid in immune response.
Specific protein examples: Enzymes?
Speed up chemical reactions in all organisms.
Specific protein examples: Cell membrane proteins?
Allow molecules to enter/exit cell and respond to chemical messengers.
What are enzymes?
Catalysts – proteins that speed up chemical reactions while reducing activation energy; involved in all metabolic reactions (dehydration synthesis and hydrolysis).
What is activation energy?
Amount of energy required to “contort the reactants” so bonds can break/change to form products; energy to jumpstart a reaction.
Enzyme characteristics: Composition?
A type of protein (made of amino acids).
Enzyme characteristics: Naming?
Named after substrate + end in -ase.
Enzyme characteristics: Specificity?
Highly specific to one type of chemical reaction (specifically shaped active site).
Enzyme characteristics: After reaction?
Unchanged and reusable.
Steps of enzyme action (e.g., sucrase)?
1. Substrate (sucrose) binds to active site. 2. Enzyme-substrate complex forms, stressing bond. 3. Bond breaks into glucose + fructose. 4. Products released, enzyme free.
Lock & Key Model of enzyme action?
Active site fits substrate exactly (like key in lock); enzyme specific to one reaction.
Induced Fit Model of enzyme action?
Active site undergoes slight shape change to fit tightly around substrate; enhances catalysis.
What factors affect enzyme activity?
pH, Temperature, Substrate Concentration.
How does pH affect enzymes?
Optimal pH for max activity; extreme pH denatures active site (changes shape, substrate no longer fits).
What is denaturation?
Enzyme’s active site changes shape so substrate no longer fits; due to extreme pH or temperature.
How does temperature affect enzymes?
Too cold: Slow molecular movement, few collisions. Optimal: Max collisions. Too hot: Denatures, reactions stop.
How does substrate concentration affect enzymes?
Activity increases with more substrates until enzymes saturated (plateaus); enzymes reusable, so extras wait.