Chapter 4 Carbon and Molecular Diversity in Life

Organic Compound

A compound containing carbon

Macromolecules

Large molecules formed by carbohydrates, lipids, and proteins

Functional Groups

Chemical groups directly involved in molecular function

Hydrocarbons

Organic molecules with only carbon and hydrogen

Isomers

Compounds with the same elements but different structures

Enantiomers

Mirror image molecules with different spatial arrangements

Valence

The number of covalent bonds an atom can form

Carbon Skeletons

Carbon chains varying in length, shape, and structure

Chemical Groups

Groups replacing hydrogens in hydrocarbons, affecting function

Hydroxyl Group

A functional group (-OH) involved in chemical reactions

Carbonyl Group

A functional group (C=O) affecting molecular function

Carboxyl Group

A functional group (-COOH) important in biochemical reactions

Amino Group

A functional group (-NH2) found in amino acids and proteins

Sulfhydryl Group

A functional group (-SH) important in protein structure

Phosphate Group

A functional group (-PO4) involved in energy transfer

Methyl Group

A functional group (-CH3) affecting gene expression

Hydroxyl group

A chemical group with the formula -OH, found in compounds like ethanol.

Carbonyl group

A chemical group with the formula C=O, present in compounds like propanal and acetone.

Carboxyl group

A chemical group with the formula -COOH, found in carboxylic acids like acetic acid.

Amino group

A chemical group with the formula -NH2, found in compounds like glycine.

Sulfhydryl group

A chemical group with the formula -SH, present in compounds like cysteine.

Phosphate group

A chemical group with the formula -OPO3, found in organic phosphates like glycerol phosphate.

Methyl group

A chemical group with the formula -CH3, present in methylated compounds like 5-Methylcytosine.

Amylose

Unbranched polysaccharide storage structure in plants

Amylopectin

Polysaccharide somewhat branched, found in plants

Glycogen

Extensively branched polysaccharide stored in animals

Cellulose

Unbranched structural polysaccharide in plant cell walls

Microfibril

Bundle of cellulose molecules forming plant cell wall

Chitin

Structural polysaccharide in arthropod exoskeleton

Lipids

Hydrophobic molecules like fats, phospholipids, steroids

Fats

Constructed from glycerol and fatty acids, for energy storage

Glycerol

Three-carbon alcohol component of fats

Fatty Acid

Consists of carboxyl group attached to carbon skeleton

Triacylglycerol

Fat molecule with three fatty acids linked to glycerol

Saturated Fatty Acids

Fats with maximum hydrogen atoms, solid at room temp

Unsaturated Fatty Acids

Fats with double bonds, liquid at room temperature

Trans Fats

Result from hydrogenating unsaturated fats, linked to health issues

Energy Storage

Major function of fats, compact way to store energy

Phospholipids

Lipids with two fatty acids and a phosphate group attached to glycerol, forming a hydrophobic tail and a hydrophilic head, major components of cell membranes.

Steroids

Lipids with a carbon skeleton of four fused rings, including cholesterol which is vital in animal cell membranes but high levels can contribute to atherosclerosis.

Proteins

Biologically functional molecules accounting for over 50% of cell mass, with diverse functions like defense, storage, transport, communication, movement, and support.

Enzymes

Proteins that act as catalysts to accelerate chemical reactions without being consumed, essential for life.

Polypeptides

Unbranched polymers made of the same 20 amino acids, forming biologically functional proteins.

Amino Acids

Organic molecules with carboxyl and amino groups, differing in properties due to unique side chains (R groups).

Peptide Bonds

Bonds linking amino acids in polypeptides, forming unique sequences with a carboxyl end (C-terminus) and an amino end (N-terminus).

Rhodopsin

Protein model with transparent shape showing internal details

Amino Acid Sequence

Determines a protein's three-dimensional structure

Protein Function

Determined by its structure

Primary Structure

Unique sequence of amino acids in a protein

Secondary Structure

Consists of coils and folds due to hydrogen bonds

Tertiary Structure

Overall shape determined by side chain interactions

Quaternary Structure

Occurs with multiple polypeptide chains

Hydrophobic Interaction

Amino acids with nonpolar side chains in protein core

Disulfide Bridges

Form between cysteine sulfurs in proteins

Denaturation

Loss of native protein structure due to environmental factors

Gene

Unit of inheritance programming polypeptide sequence

Nucleic Acids

DNA and RNA storing and transmitting genetic information

Polynucleotides

Nucleic acid polymers made of nucleotides

Nucleotide

Monomer with nitrogenous base, sugar, and phosphate

Complementary Base Pairing

Specific hydrogen bonding between DNA bases

Bioinformatics

Computer tools analyzing genomic data

Genomics

Study of large gene sets or species genomes

Proteomics

Analysis of proteins in a similar manner to genomics

Evolutionary Kinship

Assessed through similarities in DNA sequences