Lab 2 Flashcards
Compounds
-list two types with examples (4 of each)
a substance that contains atoms of two or more different elements
-Inorganic:
>simple
>water and many salts, acids and bases
-Organic:
>Contain C/H
>Large
>carbohydrates, lipids, proteins and nucleic acids.
Water as an inorganic compound
- Water is the medium for most of the chemical reactions in the body
- Blood plasma (about 90% water) transports nutrients, gases and metabolic waste products.
- When inorganic salts, acids and bases dissolve in water, they dissociate into their component ions
electrolytes
they are capable of conducting an electric current
all ions are electoryles
Salt
substance that dissociates into cations other than hydrogen ions (H+) and anions other than hydroxyl ions (OH-) when dissolved in water
Ex: NaCl, KCl, CaCO3
Acid
• is a substance which releases H+ when dissolved in water
• known as proton donors because they release (donate) protons (H+).
Ex: Hydrochloric acid (HCl)
Base
• when bases are dissolved in water, they release OH-.
• known as proton acceptors because they are substances that bind to (accept) protons (H+).
Ex: sodium hydroxide (NaOH)
homeostasis
refers to the existence of a stable internal environment.
pH Scale
- measures the concentration of hydrogen ions in a solution in moles per liter.
- The pH scale runs from 0 to 14 and is logarithmic
- A change of 1 pH unit represents a 10x change in hydrogen ion concentration
- maintain the pH of blood between 7.35 and 7.45.
pH 1-6 = acidic (H+ greater than OH-)
ph 7 = neutral (H+ = OH-)
pH 8-14 = basic / alkaline (H+ less than OH-)
Buffer
acts to resist large changes in pH by releasing hydrogen ions when the pH begins to rise and by binding hydrogen ions when the pH drops.
Ex: To neutalize HCL (stomach acid) Antacids are a group of medications designed to buffer stomach acid to treat conditions such as gastroesophageal reflux (heartburn)., they consist of a metal ion (such as magnesium or calcium) bound to a base (hydroxide or carbonate)
Test for pH (List 2)
Neutral red:
- Remains red when it is added to a neutral solution.
- When added to an acidic solution, it changes to a magenta or reddish-purple colour.
- When added to a basic solution, changes to a yellow-orange colour.
pH or litmus paper
-The paper is dipped in a sample solution and the colour change on the paper is compared with the colour corresponding to the numerical value of the pH
Carbohydrates
- Contain
- How are they classified
- What are a couple of their functions in the body
- C, H, O and usually the hydrogen and oxygen atoms occur in a 2:1 ratio.
- classified according to size as monosaccharides
- function as sources of chemical energy for generating ATP in cellular metabolism
- structural purposes (ex. DNA)
- act as markers (cell signals) on the external surface of cells
Tests for detecting carbohydrates (2)
Iodine
-reacts with starch (polysaccharid) produces a blue to blackish color reaction
Benedict’s Reagent
- Add to solution and heat to test for reducing sugars
- starts blue then cahanges to –> green, orange or red indicates a positive test for the presence of sugar
- If remains blue test is negative
Lipids
- Contain
- 3 types
- What are a couple of their functions in the body
-C, H, O(a bit)
-insoluble in polar solvents such as water
- dissolve in other lipids and in organic solvents (alcohol)
- fatty acids, triglycerides (fats and oils), phospholipids (contain phosphorous), steroids and lipoproteins.
- Functions
> energy stores, cushion organs, and insulate the body.
> structural component of cell membranes
> precursor for synthesis of steroid hormones
Test for detecting a lipid
- solubility test.
- Like dissolves like. If oil is a non-polar substance, only non-polar substances will be able to dissolve it
- Ethanol = non-polar
- Oil in Ethanol dissolves
- Oil in Water does not dissolve
Proteins
- N, C, H, O
- chains of amino acids joined by peptide bonds
Functions:
- structural framework of body tissues
- act as enzymes in biochemical reactions
- serve as membrane transporters
- act as hormones or form antibodies that defend against invading microbes.