Chapter 2: The Chemical Level of Organization Flashcards
Define Inorganic compounds
lack carbon and are structurally simple. (eg. water, salts, acids and bases)
Define Organic compounds
always contain carbon (& usually hydrogen) and are formed by covalent bonds. (eg. carbohydrates, lipids, proteins, nucleic acids, and adenosine triphosphate (ATP)
Water. What compound. Properties
Most abundant and important inorganic compound in all living organisms.
Has many important properties:
- high heat capacity. - high heat of vaporization. - polar solvent. - formed during dehydration synthesis reactions and required in hydrolysis reactions. - cushioning and lubricating effect.
Salts/Acids/Bases
• Inorganic
•All dissociate when dissolved in water, giving rise to oppositely charged ions called electrolytes.
- Salt dissociates into positive and negative ions (neither of which is H+ or OH-)
- Acid dissociates into 1 or more hydrogen ions (H+), and 1 or more negative ions. (eg. HCl → H+ + Cl-)
- Base dissociates into 1 or more hydroxyl ions (OH-) and 1 or more positive ions. (eg. NaOH → Na+ + OH-)
•H+ (hydrogon ion ) is often called a proton so Acids are called proton donors and Bases are proton acceptors
pH Scale
The pH scale has values from 0-14.
It’s based on the relative concentration of H+ in a solution (1 pH unit = a 10X change in H+ concentration).
pH < 7 is acidic: [H+] > [OH-] pH > 7 is basic: [H+] < [OH-] pH = 7 is neutral: [H+] = [OH-]
- Ph of our blood is maintained in a very very narrow range anything else will make us sicks
- pH of 8 –> pH 7 (10x change in hydrogen ion concentration)
- pH of 8 –> pH 6 (100x change in hydron ion [ ]
Buffer systems
- Buffer systems in the body minimize changes in the pH of solutions by converting strong acids or bases into weak acids or bases.
- Buffer systems mitigates strong acids or bases.
• Ex. When they dissolve in water it could give off a lot of H+ that could change the pH rapidly. A buffer is something that absorbs all the extra H+ so that the change in the H+ isn’t that great and isn’t changing the pH drastically.
What are organic compounds?
- Comprise 38-40% of total body mass.
- Contain C, H, and other functional groups.
- Other organic compounds: O, N, S, P
- Carbon (atomic # = 6) has 4 valence shell electrons so usually forms 4 covalent bonds with other elements.
- A lot of the time these organic compounds are carbon skeletons (chains of carbons with functional groups coming off them)
How are organic compounds made?
Are built by joining monomers (small molecules) together into polymers (macromolecules).
Types of Reactions Involving Water:
Dehydration Reaction:
•is a chemical reaction between two compounds where one of the products is water
2 CH3COOH → (CH3CO)2O + H2O
Hydrolysis Reaction:
•chemical compounds are broken apart by the addition of water
(CH3CO)2O + H2O → 2 CH3COOH
Carbohydrates
• Organic
• Includes sugars, glycogen, starches, and cellulose.
- Starches/cellulose are found in plants but still important to mention.
- Glucose in primary cellular fuel (carbohydrate)
- DNA/RNA there’s carbohydrates as part of the structure
• Composed of C, H, and O.
• Are main source of chemical energy for metabolism.
• Classified by # of sugar units (=size)
3 Types of Carbohydrates
• Monosaccharides: simplest, with general formula CH2O. (eg. glucose)
- CH2O shows the certain ratio in monosaccharides.
- Most Monosaccharides are pentoses (made of 5Cs.),
- some are hexoses (6Cs ex. Glucose, galactose, fructose. Molecular formula = C6H12O6. These 3 are isomers, same formula dif arrangement)
• Disaccharides: formed by a dehydration synthesis to join 2 monosaccs. (eg. sucrose)
- Sucrose = glucose + fructose
- Maltose = glucose + glucose
- Lactose = glucose + galactose
• Polysaccharides: large chains of many monosaccs. joined together. (eg. glycogen)
- Glycogen is 10s-100s of glucose linked together.
- These are used to change the blood sugar level.
- If it’s low you can break off a couple of glocoses and the blood sugar comes back up.
Lipids
- Organic
- Also composed of C, H, and O (but less O).
- Are nonpolar compounds and thus are not soluble in water.
- Non-polar = hydrophobic (water-fearing), since they’re not polar they shy away from interacting with polar molecules.
- They can’t dissolve in water (polar) but CAN dissolve in other lipids or alcohol (like dissolves like)
List 3 Lipids
a) triglycerides (fats and oils);
b) phospholipids
c) steroids.
Triglycerides (fats and oils);
- composed of glycerol and 3 fatty acid chains.
- fatty acids are hydrocarbon chains (long chain of Cs with hydrogen)
- important for storage of energy, insulation, and shock absorption.
- Either solid or liquid at room temp based only of the number of covalent bonds.
> Saturated fats = max number of hydrogens in the C chain. Solid at room temp
> Unsaturated fats = heart health. There’s one (or more) double bond between C’s. Not max H’s. (not saturated w hydrogens). The double bond created kink and can’t pack as tightly. Liquid at room temp.
Phospholipids
- composed of glycerol, 2 fatty acids, and a phosphate group (polar).
- main component of cell membranes.
- Glyceral molecule (polar head), and 2 fatty acids (nonpolar tail)
Steroids
- consist of 4 interlocking carbon rings with various side groups.
- includes cholesterol and steroid hormones.
- Cholesterol is the raw material for vitamin D which helps us absorb calcium
Proteins
- Composed of C, H, O, and N (can also have sulfur and phosphorous).
- They are polymers built from the 20 different amino acids.
Animo Acids
•20 aa
• are joined by peptide bonds (covalent bond) formed by dehydration synthesis.
- can be di-, tri-, and polypeptides. (2,3 or more aa put together)
NH2-CH-COOH
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R
There are 4 structural levels of proteins
a) Primary structure: linear sequence.
b) Secondary structure: α-helix or β-pleated sheet.
c) Tertiary structure: complex globular shape.
d) Quaternary structure: interaction of 2 or more polypeptides.
Proteins are classified as
Structural (fibrous)
Functional (globular)
Structural (fibrous)
- Stable and insoluble in water.
- Provide mechanical support and give strength.
Functional (globular)
- Less stable, H-bonds break easily.
- Are water soluble.
-help chemical reactions go forth
>Proteins can denature (loses it’s shape) and cease to function if their environment changes.
>Proteins have many important functions, including their role as enzymes.
Enzyme Activity
• Catalyst - something that increases the rate of the reaction but isn’t used up or alterned in any way over the course of the reaction
• Enzymes are biological catalysts which increase the rate of a specific chemical reaction.
• Enzymes react with a specific substrate and increase the rate at which product is formed.
E + S → E-S → P + E
- Enzymes act to decrease the amount of activation energy needed for the reaction to proceed.
- Have –ase as suffix. eg. lipase
Nucleic Acids
- Composed of C, H, O, N, & P.
- Are chains of nucleotides (monomers).
- Nucleotide = phosphate group + 5C sugar (pentose) + nitrogenous base
- Very large molecules
- Neucleotides (building blocks)
There are 2 kinds of nucleic acids:
1) Deoxyribonucleic acid (DNA)
2) Ribonucleic acid (RNA)
Deoxyribonucleic acid (DNA)
- double-stranded polymer (ladder-like shape), twisted into a double helix.
- sugar is deoxyribose.
- N-bases are A, T, C, G. (Adenine Thymine Guanine, Cytosine)
>A-T & G-C - H bonds join N-bases (“rungs”).
- Alternating sugar & phosphate mcls form the “uprights” of the ladder.
Ribonucleic acid (RNA)
- single-stranded nucleotide chain.
- sugar is ribose.
- N-bases are A, U, C, G
>(U replaces the T found in DNA).
>Uracil - are several types of RNA: rRNA, mRNA, and tRNA (all involved in protein synthesis discussed in Chapter 3).
ATP stands for
Adenosine triphosphate
Adenosine triphosphate (ATP)
- Is the molecule that cells use to perform various types of work. (eg. muscle contraction)
- Consists of the N-base adenine, 5 carbon sugar (ribose), & 3 phosphate groups.
- ATP can be broken down to adenosine diphosphate (ADP), releasing energy to be used for cellular work.
- ATP can be synthesized from ADP + P, which requires energy input provided by glucose breakdown.
- each of the phosphate are negatively charged and tightly packed
- last two are held together with a very strong covalent bond, when bond is broken a lot of energy is released, and energy can be used for muscle contractions, etc.
- Store energy by converting ADP –> ATP