Organic Compounds: Carbohydrates

Carbohydrates – include sugars and starches

Contain the elements C,H,O (H & O ratio like water, 2 H’s to 1O), ex. glucose C6H12O6

Word means “hydrated carbon”

Classified according to size: monosaccharides, disaccharides, or polysaccharides

Monosaccharides (common name = simple sugars) Means “one sugar”, single chain or single-ring structures

containing 3 to 7 carbon atoms

Important to body: glucose, fructose, galactose, ribose, deoxyribose

Pentose - 5C monosaccharide Ribose, Deoxyribose – nucleic acids and DNA

Hexose - 6C monosaccaride glucose – universal cell fuel, blood sugar

fructose – converted to glucose

galactose – converted to glucose

Organic Compounds: Carbohydrates Disaccharides – double sugars, formed when two

simple sugars are joined by a simple synthesis reaction, called dehydration synthesis

sucrose = glucose + fructose “cane sugar”(requires protein enzyme, sucrase, to decompose to simple sugars)

maltose = glucose + glucose “malt sugar”(requires protein enzyme, maltase, to decompose to simple sugars)

lactose = “in milk” glucose + galactose (requires protein enzyme, lactase, to decompose to simple sugars)

All double sugars are too large to pass through cell membrane, must be broken down to be absorbed by process hydrolysis – water added to bond, bond breaks, then simple sugar is released

Organic Compounds: Carbohydrates

Polysaccharides “many sugars” – are long, branching chains of linked simple sugars

Because they are large, insoluble molecules, ideal for storage, also lack sweetness of simple & double sugars

Glycogen- storage polysaccharide found in animal tissues (liver & muscles)

Starch – storage polysaccharide formed by plants (potatoes & carrots)

Cellulose (made of a different isomer of glucose, beta-ringed glucose, and cannot be digested by humans)

Carbohydrate Functions:

ready, easily used source of energy for cells to make ATP

part of structure of DNA and RNA (pentose sugars - ribose and deoxyribose)

recognition sites on cell membrane surfaces

Organic Compounds: Lipids Lipids – organic molecules that contain: C, H, O

Carbon & Hydrogen far outnumber the Oxygen atoms ex. C57H110O6 - tristearin

Most are insoluble in water, but will dissolve in other lipids and in other solvent such as acetone and alcohol

Presence of P & N in some of the lipids

Triglycerides (Neutral Fats) – composed of two types of building blocks: fatty acids & glycerol Synthesis involves attachment of 3 fatty acids to a single

glycerol molecule-results in an E shaped molecule that resembles the tines of a fork

Maybe solid-typical of animal fats or liquid- plant oils

Animal oils tend to be saturated, plant oils are unsaturated saturated fats- all carbons single bonds

unsaturated fats- carbons have some double and triple bonds

Most abundant & concentrated source of energy-when oxidized yield large amounts of energy

Stored chiefly in fat deposits beneath skin & around organs, where help insulate body and protect deep tissues

Triglycerides

Organic Compounds: Lipids Phospholipids- similar to neutral, but differ in that a

phosphorus group is attached & takes place of one

of fatty acid chains

Phosphorus portion “the head” contains an electrical

charge gives special chemical properties and polarity

Consists of a polar head attracts & interacts with water

& ions but the nonpolar tail does not interact

Found in cell membranes and allows cells to be

selective about what may enter or leave

Steroids –flat molecules formed of 4 interlocking rings,

look different than other 2 lipids, but act similar (C,H

and lipid soluble)

Examples - cholesterol, vitamin D, hormones, bile salts

Cholesterol from food & in cell membranes, abundant in

brain, provides raw material to produce vitamin D, some

hormones, & bile salts

Phospholipids

Steroids

Organic Compounds: Proteins Proteins- a nitrogenous substance made up of amino acids

Contains C,H,O,N & sometimes S

Account for over 50% of the organic material in the body, and most varied in their functions of all the organic molecules

amino acids – are the building blocks of proteins, about 20 types Have 3 components:

-COOH (carboxyl) group – allow them to act as acids

-NH2 (amine) group – gives basic properties

R-group – what is different for each that makes them chemically unique

Amino acids joined in chains to form complex protein molecules that contain from 50 to thousands of amino acids Polypeptide – fewer than 50 amino acids

Each amino acid is distinct, sequence in which they are bound produce proteins that vary widely in both structure and function

Classifying Proteins

Fibrous Proteins- are strand like, are also called

“structural proteins”

Appear most often in body structures, important

in binding structures together and in providing

strength to certain body tissues, very stable

Ex. - Collagen – found in bones, cartilage, and

tendons-most abundant protein in body

ex. Keratin – found in hair, nails, and makes the

skin tough

Classifying Proteins Globular Proteins – mobile, spherical molecules that

play critical roles in many biological processes, they do things rather than just form structures, are also called “functional proteins”, not stable

Some are antibodies (provide immunity), hormones (regulate growth & development), enzymes (catalysts for chemical reactions)

Hydrogen bonds are critically important in maintaining structure, but are fragile & easily broken by heat and pH changes

When the 3 dimensional structure is destroyed, called denatured proteins, no longer can perform their roles (function depends on structure)

active sites – are structure on their surface that “fit” or interact with other molecules, ex. hemoglobin- has pepsin, that is inactivate by blood pH becoming to alkaline

Classifying Proteins

Enzymes- are functional proteins that act as

biological catalysts

Catalyst- substance that increases the rate

of a chemical reaction without be

consumed or changed itself

change the energy of activation for a chemical

reaction

Enzymes usually end in –ase

Enzymes are often produced in a inactive

form and must be activated before can

function, in some a cases are inactivated

immediately after function(blood clotting)

ProteinsSupport structural proteins (e.g., keratin, collagen)

Enzymes speed up chemical reactions

Transport cell membranes channels, transporters in blood

(e.g., Hemoglobin)

Defense antibodies of the immune system

Hormones cell signaling (e.g., insulin)

Motion contractile proteins (e.g., actin, myosin)

Organic Compounds: Nucleic Acids

Nucleic acids – make up genes, composed of

carbon, oxygen, hydrogen, nitrogen, and

phosphorous atoms

Largest biological molecules in the body

Their building blocks, the nucleotide, are very

complex

3 components: 1)nitrogen containing base, 2)

pentose (5 carbon sugar), & 3) phosphate group

5 types of Nitrogen bases: 1)adenine(A), 2) guanine

(G), 3) cytosine (C), 4) thymine(T), & 5) uracil (U)

Two major kinds of nucleic acid: 1. deoxyribonucleic

acid (DNA) & 2. ribonucleic acid (RNA)

Nucleotide Structure

Nucleic Acids: DNA Is the genetic material found in the nucleus

Replicate itself exactly before cell divides

Provides instructions for building every cell in the

body

Long double chain of nucleotides

Bases are A,G,T,C

Sugar deoxyribose

Double stranded helix shape-chains held together

by hydrogen bonds between bases (spiral

staircase)

Complementary base pairs – A binds with T, and G

binds with C

DNA

Nucleic Acids: RNA Located outside nucleus and can be considered the

“molecular slave” of DNA

Caries out the orders from the DNA for protein synthesis

Consists of single nucleotide strands

Bases A,G, C, and U instead of T

Sugar is ribose

3 types of RNA: 1) messenger RNA, 2) ribosomal RNA, & 3)

transfer RNA, each w/specific role in carrying out DNA’s

instructions

Messenger RNA – carries info. For building protein from DNA

genes to ribosomes

Transfer RNA – ferries/caries amino acids to the ribosomes

Ribosomal RNA – forms part of the ribosomes, where it

oversees the “translation” of the message & the binding

together of amino acids to from proteins

ATP Adenosine Triphosphate (ATP) – provides a form of chemical

energy that is useable by all body cells

w/out ATP, molecules cannot be made or broken down, cells cannot maintain their boundaries, all life processed would stop

Glucose is most important “fuel”, but none of its chemical energy contained in its bonds can be used directly

Energy released as glucose instead is catabolized (captured) and stored in the bond of ATP molecules as small “packets” of energy

Structurally it is a modified nucleotide, consists of an adenine base, ribose sugar, & 3 phosphate groups

When the high energy phosphate bonds are broken by hydrolysis, energy that can be used immediately by the cell is liberated

ATP be compared to a tightly coiled spring that is ready to uncoil w/tremendous energy when the “catch” is released

How ATP Drives Cellular Work

THE BIG PICTURE

Chemistry is essential for life…