Download Unit 1: Biology Review

Anatomy Fall 2009
Unit 1: Biology Review
Salts, Biological Elements, Acids & Bases, Biomolecules
Salts & Biological Elements:
- Salt: A compound composes of a metal and a nonmetal, which dissociates
and ionizes in water/solution.
- Salts are important to the body because they allow for electrical current,
essential to cell communication and muscle contraction.
- All biological compounds contain a few common elements: C, H, O, N, P, S.
- However, there are also other elements common to our body, but not always
found in organic compounds: Ca, P, K, Na, Cl, Fe
- Calcium = bones + teeth
- Phosphorus = (a little bit bones + teeth) mostly ATP and nucleotides
- Potassium, Sodium, Chlorine = nerve impulses and muscle contraction
- Iron = part of hemoglobin, allowing for binding and carrying of oxygen
through blood
Acids & Bases:
- Acids and bases are also electrolytes. This is because both dissociate in
solution, and ionize, forming separate charged particles.
- Acids release hydrogen ions (positive) when they dissociate in solution.
- Common acids in our body are hydrochloric acid (stomach), acetic acid (carb
and protein digestion) and carbonic acid (blood).
- Bases release hydroxide ions (negative) when they dissociate in solution.
- A common base is bicarbonate (blood).
- pH is the measurement of the concentration of hydrogen ions (and hydroxide
ions) in solution.
- 0-6.9 represents acidic solutions, with a higher hydrogen ion concentration.
7.1-14 represents basic solutions, with a lower hydrogen ion concentration
(higher hydroxide concentration). 7 represents a neutral solution.
Organic / Biomolecules:
- There are 4 types of biomolecules: carbohydrates, lipids, proteins and nucleic
acids.
- Carbohydrates function primarily for short term and intermediate energy use.
However carbohydrates can also provide structure.
- There are 3 classes of carbohydrates: monosaccharides, disaccharides, and
polysaccharides.
- Monosaccharide = single sugar (glucose, fructose, galactose, ribose,
deoxyribose)
- Disaccharide = two/double sugar
- Both monosaccharides and disaccharides give food a sweet taste. However,
because they are such simple molecules, with few bonds, they release minimal
energy extremely fast (not ideal).
- Polysaccharides = complex carbs (many sugars)
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Polysaccharides release more energy, over a longer period of time because
there are simply more bonds to break.
You can form complex carbs through dehydration synthesis/reactions,
removing water, and binding simpler mono/disaccharides.
To break down the carbs, your body uses hydrolysis reactions to add water,
and separate larger saccharides.
Lipids are primarily used for long term energy storage, but also for membrane
structure/function, and cell communication.
Neutral fats are oils and “fat” as you would call it.
Steroids and hormones are also types of lipids and function to control growth
and reproduction.
Phospholipids are extremely important, as they form the membranes around
your cells. Phospholipids have a hydrophyllic (water loving, polar) head, and
a hydrophobic (nonpolar, water fearing) tail/s.
Proteins serve a variety of functions in your body including structure and
reaction catalysis.
Proteins are composed of uniquely sequenced amino acids. Depending on the
sequence of the amino acids, each protein has an extremely unique and
complex structure, along with a unique function.
Enzymes are a type of protein which catalyze reactions. They do this by
lowering the energy of activation, so that the reaction may proceed more
quickly (while using less energy).
Proteins are the “product of DNA”. Meaning, your DNA is just an instruction
manual. The proteins are the result, or what happens after you follow those
directions/instructions.
Nucleic Acids function to store genetic information.
There are 2 types of nucleic acids: DNA, RNA
All nucleic acids are made of a basic unit: nucleotide. Nucleotides are made
of a phosphate group, a pentose sugar, and a nitrogenous base.
DNA contains deoxyribose (for its sugar) and nitrogenous bases: A, T, G, C.
RNA contains ribose (for its sugar) and nitrogenous bases: A, U, G, C
Both are helical, however DNA is a double helix, RNA is a single strand.