bio 1: 3

The carbon atom

Considered the 'backbone' of life; stable across a wide temperature range and forms nonpolar bonds with H and polar bonds with O.

What four atoms is carbon usually found in?

H,O,N,S

Hydrocarbons

Molecules with a lot of C-H bonds

Functional groups

define the function of the organic molecule

Amino functional group (-NH2)

Weakly basic, polar, can accept H+, and forms peptide bonds in amino acids.

Carbonyl functional group (-CO)

Polar, highly chemically reactive, and forms hydrogen bonds (found in steroids, waxes, and proteins).

Aldehyde (–CHO)

Linear forms of sugars and some odor molecules

Carboxyl functional group (-COOH)

Acidic (gives up H+ in water) and forms part of peptide bonds in amino acids and fatty acids.

Hydroxyl functional group (-OH)

Polar and forms hydrogen bonds with water (found in steroids, alcohol, carbohydrates, and amino acids).

Methyl functional group (-CH3)

A nonpolar group that may be attached to DNA, proteins, and carbohydrates.

Phosphate functional group (-PO4 2-)

Polar, weakly acidic, and negatively charged; found in nucleic acids, ATP, and phospholipids.

Sulfate (-SO4^-)

Polar; negatively charged at typical pH of living organisms, May be attached to carbohydrates, proteins, and lipids

Sulfhydryl functional group (-SH)

Polar group that forms disulfide bridges in many proteins (found in cysteine).

isomers

two molecules with an identical molecular formula, but different structures and characteristics

Structural isomers

Molecules that contain the same atoms but have different bonding relationships.

Stereoisomers

Molecules with identical bonding relationships but differing spatial positioning of atoms.

Cis-trans isomers

positioning around a double bond

Enantiomers

Mirror-image molecules whose differing orientation leads to distinct binding abilities and enzyme recognition.

Macromolecules

large, complex organic molecules; typically made of thousands or millions of atoms

_____ subunits of _____

monomers, polymers

condensation reactions

Link monomers to form polymers

how are polymers made? (reaction)

condensation reaction

Dehydration (condensation) reaction

An enzyme-catalyzed reaction that links monomers to form polymers by releasing a water molecule.

Hydrolysis reaction

An enzyme-catalyzed reaction that cleaves polymers into monomers by adding water.

what are the 4 major types of organic molecules & macromolecules?

carbohydrates, lipids, proteins, nucleic acids

Carbohydrates

Simple & complex sugars, Monomers are called monosaccharides, Contain C, H, O

Monosaccharides

The simplest sugars (carbohydrate monomers) with linear or ring structures containing commonly 5 or 6 carbons.

Disaccharides

Monosaccharides joined by dehydration reactions via glycosidic bonds (e.g., sucrose, maltose, lactose).

Glycosidic bonds

occur between the monomers of carbohydrates aka monosaccharides

Polysaccharides

long polymers of monosaccharides

Storage polysaccharides

Long carbohydrate polymers used for energy storage, such as starch and glycogen.

Structural polysaccharides

Long carbohydrate polymers used for structural support, such as cellulose, chitin, and peptidoglycan.

Lipids

Organic molecules composed mainly of C and H atoms that are nonpolar and very insoluble (hydrophobic).

Fat

a mixture of triglycerides

Triglycerides (Fats)

Lipids consisting of glycerol and three fatty acids joined by dehydration reactions.

Saturated fatty acids

Fatty acids with no double bonds, forming a linear structure that is solid at room temperature.

Unsaturated fatty acids

Fatty acids with one or more double bonds, forming a 'kinky' structure that is liquid at room temperature.

animal fats are usually ____ fats

saturated (solid at room temp)

plant fats are usually ____ fats

unsaturated (liquid at room temp)

Fats are important for____

energy storage

Phospholipids

Amphipathic molecules composed of glycerol, a phosphate group, and two fatty acids, forming cell membranes.

phospholipid bilayer

Two layers of phospholipids,Hydrophilic head,Hydrophobic tails

Steroids

Lipids characterized by a carbon skeleton consisting of four fused rings (e.g., cholesterol, estrogen, testosterone).

Waxes

complex lipids – hundreds of kinds(Used to prevent water loss)

Proteins

Mainly made of C, H, N, O, made of one or more polypeptides

Amino acids

The monomers of proteins, featuring a common structure with a variable side chain (R-group) that determines function.

polypeptides

Polymers of amino acids

Protein functions(7)

Gene expression, Movement, Defense, Metabolism, Cell signaling, Provide structure, Transport

Peptide bond

A strong covalent bond formed between the carboxyl group of one amino acid and the amino group of another via dehydration.

Primary protein structure

The specific linear sequence of amino acids in a polypeptide chain.

Secondary protein structure

The folding of the amino acid sequence into a spiral (alpha-helix) or sheet (beta-sheet).

Tertiary protein structure

The complex three-dimensional shape of a single polypeptide chain.

Quaternary protein structure

The assembly of multiple polypeptide chains into a functional protein complex (e.g., hemoglobin).

Protein denaturation

The disruption of a protein's normal folding and 3D shape caused by extreme heat, pH shifts, or heavy metals.

Protein(structure sense)

refers to the stable 3D shape with biological activity

5 factors that promote protein folding and stability

1. Hydrogen bonds 2. Ionic bonds and polar interactions 3. Hydrophobic effect 4. van der Waals forces 5. Disulfide bridges (when the –SH groups in two cysteine side chains are linked together)

Denaturation

(in proteins) when folding is disrupted

conditions that might cause protein denaturation

Heat, pH extremes, Organic solvents, Heavy metal ions, Physical agitation, UV radiation

Nucleic acids

Macromolecules (DNA and RNA) responsible for storing, expressing, and transmitting genetic information.

DNA (Deoxyribonucleic acid)

stores genetic information encoded in the sequence of nucleotide monomers

RNA (Ribonucleic acid)

decodes DNA into instructions for linking together specific sequences of amino acids to form a polypeptide chain

Nucleic acid polymers are made up of

nucleotide monomers

Purine bases

Adenine (A), Guanine (G)

Pyrimidine bases

Cytosine (C), Thymine (T), Uracil (U)

Nucleotide components

The three parts of a nucleotide monomer: a pentose sugar, a phosphate group, and a nitrogenous base.

DNA vs. RNA sugar

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

DNA base pairing rules

Adenine pairs with Thymine (A-T), and Cytosine pairs with Guanine (C-G) via hydrogen bonding.

RNA has _____ nucleotide whilst DNA has ____

U, T