What are the 4 categories of carbon compounds?
- Carbohydrates
- Lipids
- Proteins
- Nucleotides and nucleic acid
What are the functional groups of carbon compounds?
Small clusters of atoms attached to carbon backbone, these determine many of the properties of organic molecules:
Hydroxyl - OH Methyl - CH2 Carboxyl - COOH Amino - NH3 Phosphate - H3PO4
Describe Monomers Polymers and Macro Molecules
Macromolecules - very large organic molecules (high weight, usually proteins/ DNA)
Monomers - an identical or similar subunit
Polymers - Molecules made of a repetitive series of identical or similar subunits (monomers)
What is Polymerization?
Joining monomers to form a polymer
In what ways can Polymerization occur?
Dehydration synthesis (condensation) is how living cells form polymers.
Hydrolysis - Opposite of dehydration synthesis
Explain Dehydration Synthesis
Monomers covalently bond together to form a polymer with the removal of a water molecule.
Hydroxyl -OH group is removed from one monomer, and hydrogen H+ from another, producing water as by-product)
Explain Hydrolysis
Splitting a polymer (lysis) by the addition of a water molecule (hydro). A covalent bond is broken.
All digestion reactions consists of hydrolysis reactions.
What is a Carbohydrate?*
*(important to know)
Hydrophilic (interacts with water) organic molecule
(CH2O)n = number of carbon atoms for glucose, n=6 so formula is C6H12O6
**2:1 ration of hydrogen to oxygen **
What are Monosaccharides?
Simplest carbohydrates (simple sugars)
What are the 3 important monosaccharides?
Glucose, Galactose and Fructose - they all have the same molecular formula (C6H12O6 - they are isomers)
Produced by digestion of complex carbohydrates
Glucose is blood sugar
What are Disaccharides?
Sugar molecule composed of 2 monosaccharides.
What are the 3 important disaccharides?
Sucrose - table sugar (glucose +fructose)
Lactose - sugar in milk (glucose + galactose)
Maltose - grain products (glucose + glucose)
What are Polysaccharides?
Long chains of glucose
What are the 3 polysaccharides of interest in humans?*
Glycogen - energy storage polysaccharide in animals.
(made by liver, muscles, brain, uterus and vagina. Live produces glycogen after a meal when glucose level is high then breaks it down between meals to maintain blood glucose levels. Muscles store glycogen for own energy needs. Uterus uses glycogen to nourish embryo)
Starch - Energy Storage polysaccharide in plants (only significant digestible polysaccharide in the human diet)
Cellulose - Structural molecule of plant cell walls (fiber in our diet)
What are the Carbohydrate Functions?
To quickly mobilize our source of energy. (all digested carbohydrates are converted to glucose and are oxidized to make ATP)
What are Conjugated carbohydrates?
covalently bound to lipid or protein. They include:
Glycolipids - external surface of the cell membrane
Glycoproteins - external surface of the cell membrane, make up mucus of respiratory and digestive tracts
Proteoglycans (mucopolysaccharides) - gels that hold cells and tissues together. They form gelatinous filler in umbilical cord and eyes. They provide joint lubrication. They are tough and rubbery texture of cartilage.
What are Lipids?*
Hydrophobic organic molecule composed of carbon, hydrogen and oxygen. They have a high ratio of hydrogen to oxygen.
Less oxidized than carbohydrates and thus has more calories/gram***
*remember hydrophobic - does not interact with water, does not dissolve completely, leaves films like butter in water.
What are the 5 primary types of Lipids in humans?
Fatty Acids Triglycerides Phospholipids Eicosanoids Steroids
What are Fatty Acids?*
Chain of 4 to 24 Carbon atoms. Carboxyl (acid) group on one end and methyl group on the other and hydrogen bonded along the sides.
How are Fatty Acids Classified?
saturated - carbon atoms saturated with hydrogen
unsaturated - contains C=C bonds without hydrogen
polyunsaturated - contains many C=C bonds
essential fatty acids - obtained from diet, body cannot synthesize.
What are Triglycerides (Neutral Fats)?*
3 fatty acids covalently bonded to three carbon alcohol, glycerol molecules.
- each bond formed by dehydration synthesis. one joined to glycerol, fatty acids can no longer donate protons - neutral fats.
- broken down by hydrolysis.
Triglycerides at room temperature:
When liquid, called oils. Often polyunsaturated fats from plants. When solid, called Fat, saturated fats from animals.
What are Triglycerides primary function?
Energy Storage, insulation and shock absorption (adipose tissue)
What are Phospholipids?*
Similar to neutral fat except that one fatty acid replaced by a phosphate group.
Structural foundation of a cell membrane.
Amphiphilic - fatty acid “tails” are hydrophobic, Phosphate “head” is hydrophilic
What are Eicosanoids?*
20 carbon compounds derived from a fatty acid called Arachidonic acid.
hormone - like chemical signals between cells.
includes prostaglandins - produced in all tissues. play roles in inflammation, blood clotting, hormone action, labour contractions, blood vessel diameter.
What is a Steroid?
A lipid with 17 of its carbon atoms in 4 rings.
What is Cholesterol?*
The “parent” steroid from which the other steroids are synthesized.
- synthesized only by animals, especially liver cells. 15% from diet, 85% internally synthesized.
- important component of cell membranes. required for proper nervous system function.
What are Proteins?
A polymer of Amino acids.
What is an Amino Acid?
central carbon with 3 attachments.
- Amino group (NH2), carboxyl group (COOH) and radical group (R Group)
- 20 amino acids used to make the proteins are identical except for the radical (R) group. Properties of amino acid determined by R group.
What is a Peptide?
Any molecule composed of two or more amino acids joined by peptide bonds.
What is a Peptide Bond?
Joins the amino group of one amino acid to the carboxyl group of the next. Formed by dehydration synthesis.
What are the 4 structures and shapes of Protein?
Primary Structure - proteins sequence amino acid which is encoded in the genes.
Secondary structure - coiled or folded shape held together by hydrogen bonds. Alpha Helix (spring shape) and Beta Helix (pleated, ribbon shape)
Tertiary Structure - further bending and folding of proteins in globular and fibrous shapes. Globular proteins are compact in cell membrane and proteins that must move freely in body fluid. Fibrous proteins - slender filaments better suited for roles as in muscle contraction and strengthening the skin.
Quaternary structure - associations of two or more separate polypeptide chains. functional conformation - 3D shape
What is protein Conformation?*
unique 3D shape of protein crucial to function.
Ability to reversibly change their conformation. With enzyme function, muscle contraction, opening and closing of cell membrane pores.
What is protein Denaturation?*
Extreme conformational change that destroys function. Extreme heat or pH.
What are more protein functions?
Structure - Keratin ( strength to hair, nails, skin surface)
Communication - some hormones and other cell to cell signals. receptors to which signal molecules bind
Membrane transport - channels in cell membranes that governs what passes through. Carrier proteins transport solutes particles to other side of membrane. Turn nerve muscle activity on and off.
***Catalysis - enzymes, use lower activation energy.
Recognition and protection - immune recognition, antibodies and clotting proteins.
Movement - Motor proteins are molecules with the ability to change shape repeatedly
Cell Adhesion - proteins bind cells together. immune cells to bind to cancer cells. Keeps tissues from falling apart.
What are Enzymes?
Proteins that function as biological catalysts.
they permit reactions to occur rapidly at normal body temp
Substrate - substance an enzyme acts upon.
Enzymes will lower activation energy - energy needed to get reaction started.
How does Enzymes work?
Enzymes breaks covalent bonds between monomers in substrate. Adding H+ and OH- from water - Hydrolysis.
reaction products released - glucose and fructose
Enzyme remains unchanged and is ready to repeat the process
Describe Enzymatic Action
Reusability of enzymes - enzymes are not consumed by the reactions
Astonishing Speed - one enzyme molecule can consume millions of substrate molecules per minute
Factors that change enzyme shape - pH and Temp. Alters or destroys the ability of the enzyme to bind to substrate.
What are the 3 components of Nucleotides?
Nitrogenous base - single or double carbon-nitrogen ring
Sugar (monosaccharide)
one or more Phosphate groups
What is ATP?
best known nucleotide. Adenosine Triphosphate.
- Adenine (nitrogenous base)
- Ribose (sugar)
- Phosphate groups (3)
Describe Adenosine Triphosphate (ATP)
body’s most important energy-transfer molecule.
briefly stores energy gained from exergonic reactions.
releases it within seconds for physiological work.
Holds energy in covalent bonds.
What is Adenosine Triphosphatases (ATPases)
they hydrolyze the 3rd high energy phosphate bond. Separates into ADP + Pi + energy.
what is Phosphorylation?
addition of free phosphate group to another molecule. Carried out by enzymes called kinases (phosphokinases)
What are Nucleic Acids?*
Polymers of nucleotides.
DNA - deoxyribonucleic acid - 100 million to 1 billion nucleotides long constitutes genes. Instructions for synthesizing all of the body’s proteins. Transfers hereditary information from cell to cell and generation to generation
What is RNA?
Ribonucleic Acid - 3 types
Messenger RNA
Ribosomal RNA
Transfer RNA
70-10,000 nucleotides long
carries out genetic instructions for synthesizing proteins
assembles amino acids in the right order to produce proteins