organic compounds. important organic compounds carbohydrates lipids proteins nucleic acid atp...
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Organic Compounds
Important Organic Compounds
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acid
• ATP (Adenosine TriPhosphate)
Carbohydrates (only 2 -3% of body mass)– Contain carbon, hydrogen, and oxygen
(hydrated carbon)– Include sugars,starches, glycogens, and
cellulose– Classified according to size
• Monosaccharides• Disaccharides• Polysaccharides
Monosaccharides- “one sugar” monosaccharides are simple sugars occurring in single chain or single ring structures with 3-7 carbon atoms. Glucose (blood sugar) is the universal cellular fuel.
Diabetics should take glucose reading at least 4 times a day, before meals and at bedtime. Aim for a range between 80 - 120 before meals and 100 - 140 at bedtime. It will go up and down over the course of the day.
Carbohydrates
Figure 2.13a–b
Disaccharides- “double sugars” Formed when two simple sugars are joined by dehydration synthesis. In this reaction a water molecule is lost as the bond is formed.
Sucrose is a disaccharide that consists of both glucose and fructose linked together.
Dehydration Synthesis- a process by which a larger molecule is synthesized from smaller ones by the removal of a water molecule at each site of bond formation.
Carbohydrates
Figure 2.14
Important Disaccharides-sucrose (glucose-fructose)-cane sugarlactose (glucose-galactose)-milk sugarmaltose (glucose-glucose)-malt sugar
Since double sugars are too large to pass across cell membranes they are broken down (digested) to monosaccharide units. This is accomplished by hydrolysis.
Galactosemia (galactos =milk, -emia
=in the blood)
An disorder in which galactose builds up in the blood due to the body’s lack of the enzyme that converts galactose to glucose. What would you suggest for treatment for an infant that had this disorder? (Hint: think about where galactose comes from…)
No Lactose!!!!
Hydrolysis-the process in which water is used to split a substance into smaller particles.
SUBSTRATE-a substance on which an enzyme reacts during a chemical reaction. In this case sucrase slightly changes the sucrose weakening the chemical bonds between the glucose and fructose allowing the sucrose to break apart and be digested.
Sucrose is the substrate.
Sucrase is the enzyme responsible for digesting sucrose.
Polysaccharides- “many sugars”. Long branching chains of linked simple sugars. Polysaccharides are large insoluble molecules that are ideal storage products. Carbohydrates provide a ready easily usable source of food energy for cells. Polysaccharides are long polymers consisting of up to hundreds of glucose molecules.
Carbohydrates
Figure 2.13c
Starch-the storage polysaccharide formed by plants. We ingest it in the form of starchy foods like grains and root vegetables.
Glycogen-a polysaccharide found in animal tissues (primarily in the muscles and the liver).
Endoplasmic Reticulum
Shown Here: liver cells where smooth ER helps to metabolize stored glycogen (black rosettes) and metabolize toxic substances.
Figure 2.13c
Lipids (18 – 25% of body mass)– Contain carbon, hydrogen, and oxygen
• Carbon and hydrogen outnumber oxygen. (ex: Tristearin is a triglyceride that forms the principle fat in beef. (C57H110O6)
LipidsInsoluble in water (non-polar molecules), but
readily dissolve in other lipids and organic solvents such as alcohol.
• Common lipids in the human body– Neutral fats (triglycerides)
• Found in fat deposits• Composed of fatty acids and glycerol• The body’s most abundant source of stored
energy. Found in fat deposits in subcutaneous tissue and around organs.
The synthesis of triglycerides involves the attachment of three fatty acids to a glycerol molecule forming an E-shaped molecule. Molecules vary as the fatty acids change.
Lipids
Figure 2.17
• Saturated vs. Unsaturated Fatty AcidsSaturated-single covalent bonds, straight chain,
which packs tightly together forming a solid at room temperature.
Unsaturated-double covalent bonds cause fatty acid chains to kink forming a liquid at room temperature.
• Trans Fat-oils that have been solidified by addition of hydrogen atoms at sites of double carbon bonds.
Phospholipids• Form cell membranes• Similar to triglycerides except that a phosphate
group replaces one of the fatty acid chains.
Lipids
Figure 2.15b
Phospholipids
Since the phosphorous containing head bears an electrical charge a phospholipid has unique chemical properties that enable the control of materials into and out of the cell. (amphipathic: amphi = on both sides)
Steroids-flat molecules composed of four interlocking rings. Include cholesterol, bile salts, vitamin D, and some hormones
Testosterone
Figure 2.15c
• Cholesterol– The basis for all steroids made in the body.
Cholesterol is found in cell membranes and is the raw material of Vitamin D, steroid hormones, and bile salts.
• Other Lipids
a) Carotenes – visual pigments
b) Vitamin E – wound healing
c) Vitamin K – Blood clotting proteins
d) Lipoproteins - transportation of lipids in blood
Table 2.7
• Proteins– Made of amino acids
• Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur
Figure 2.16
• Proteins– Amino Acid Structure-there are about 20
common amino acids that make up proteins they have the basic structure seen below.
Figure 2.16
• Proteins– Amino acids are joined together during protein
synthesis to form large complex protein molecules containing from 50 to thousands of amino acids.
Figure 2.16
Proteins (12 -18% of body mass)
• Account for over half of the body’s organic matter– Provide construction materials for body
tissues– Play a vital role in cell function
• Act as enzymes, hormones, and antibodies
Protein Structure• Primary Structure – unique sequence
of amino acids; genetically determined
• Secondary Structure – repeated twisting or folding of neighboring amino acids in the polypeptide chain; alpha helixes (spirals) or pleated sheets; stabilized by hydrogen bonds
• Tertiary Structure – three dimensional shape of the polpeptide chain; unique tertiary structure to each protein (enzyme function)
• Quarternary Structure – arrangement of individual polypeptide chains relative to one another; only seen in some proteins
Figure 2.17a
Proteins
• Fibrous proteins– Also known as
structural proteins– Appear in body
structures– Examples include
collagen and keratin– Stable
Figure 2.17a
Collagen-the protein of bones, cartilage, and tendons (and plastic surgery ).
Figure 2.17a
Collagen-
Figure 2.17a
Keratin-the protein of hair and nails. Also makes skin tough.
Figure 2.17b
Proteins
• Globular proteins– Also known as
functional proteins– Function as antibodies,
hormones, or enzymes (regulatory, immunological,catalytic,transport, contractile)
– Can be denatured
Figure 2.17b
Globular proteins are unstable and can be easily denatured. Changes in heat or pH levels can result in the breaking of hydrogen bonds, known as denaturing. (NOTE: we don’t KILL proteins!!!)
Figure 2.17b
When proteins denature their 3-Dimensional structures are destroyed and can no longer perform their physiological roles as the shape of active sites are changed.
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SUBSTRATE-a substance on which an enzyme reacts during a chemical reaction. In this case sucrase slightly changes the sucrose weakening the chemical bonds between the glucose and fructose allowing the sucrose to break apart and be digested.
Sucrose is the substrate.
Sucrase is the enzyme responsible for digesting sucrose.
Figure 2.18a
Enzymes act as biological catalysts by increasing the rate of chemical reactions
Only small amounts of enzymes are required in the body as enzymes are not consumed during their reactions. Enzymes are categorized by the type of reaction that they catalyze ie:
hydrolases add water
oxidases cause oxidation
http://www.kscience.co.uk/animations/anim_2.htm
Galactosemia (galactos =milk; esemia =in the blood)
• An inherited disorder in which galactose is not metabolized due to a faulty or missing enzyme
• Infants fail to thrive within week after birth due to anorexia, vomiting and diarrhea
• If Lactose undergoes hydrolysis to form galactose and glucose, what would you suggest for treatment???
• Nucleic Acids– Provide blueprint of life– Nucleotide bases
• A = Adenine• G = Guanine• C = Cytosine• T = Thymine• U = Uracil
– Make DNA and RNA
Figure 2.19a
Nucleic Acids• Deoxyribonucleic
acid (DNA)– Organized by
complimentary bases to form double helix
– Replicates before cell division
– Provides instructions for every protein in the body
Figure 2.19c
Adenosine Triphosphate (ATP)
Figure 2.20a
Adenosine triphosphate (ATP) the chemical energy used by all cells. Glucose is the main source of energy for cells; however the energy stored in its bonds can’t be used by cells. Our bodies catabolize glucose and capture and store the energy in the bonds of ATP.
The energy in ATP is released by breaking high energy phosphate bond– ATP is replenished by oxidation of food fuels
Figure 2.21
+ADP
Solute
Contractedmuscle cell
Product made
Relaxedmuscle cell
Reactants
Transport work
Mechanical work
Chemical work
Membraneprotein
Solute transported
Energy liberated duringoxidation of food fuelsused to regenerate ATP
ATP
P
P
P
X
Y
(a)
(b)
(c)
YX
P P
+
Figure 2.21, step 1
Solute
Transport work
Membraneprotein
ATP
(a)
P
Figure 2.21, step 2
+ADP
Solute
Transport work
Membraneprotein
Solute transported
ATPP
(a)
P P
Figure 2.21, step 3
Relaxedmuscle cell
Mechanical work
ATP
(b)
Figure 2.21, step 4
+ADP
Contractedmuscle cell
Relaxedmuscle cell
Mechanical work
ATPP
(b)
Figure 2.21, step 5
Reactants
Chemical work
ATP
PX
Y
(c)
+
Figure 2.21, step 6
+ADP
Product madeReactants
Chemical work
ATP
P
P
P
X
Y
(c)
YX
+
Figure 2.21, step 7
+ADP
Solute
Contractedmuscle cell
Product made
Relaxedmuscle cell
Reactants
Transport work
Mechanical work
Chemical work
Membraneprotein
Solute transported
ATP
P
P
P
X
Y
(a)
(b)
(c)
YX
P P
+
Figure 2.21, step 8
+ADP
Solute
Contractedmuscle cell
Product made
Relaxedmuscle cell
Reactants
Transport work
Mechanical work
Chemical work
Membraneprotein
Solute transported
Energy liberated duringoxidation of food fuelsused to regenerate ATP
ATP
P
P
P
X
Y
(a)
(b)
(c)
YX
P P
+