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

+