organic compounds: carbohydrates...organic compounds: proteins proteins- a nitrogenous substance...
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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
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
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)
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
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