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.
Test for detecting a protein
Biuret reagent
- A purple color is produced when a protein is combined with biuret reagent
Nucleic acids
-P, N, C, H, O
-a chain of repeating subunits (monomers) called nucleotides
-three components:
>a nitrogenous base
>a five carbon sugar deoxyribose or ribose
>a phosphate group.
- DNA forms the genetic material inside each human cell
- RNA relays instructions from genes to guide the synthesis of proteins
Chromatin
- Within the nucleus of a cell
- composed of deoxyribonucleic acid, proteins and some ribonucleic acid.
- In a dividing cell, the DNA becomes highly folded and condensed forming chromosomes
The cell
a highly organized unit that is ceaselessly engaged in dynamic biochemical activities.
organelles
Molecules can combine to form a variety of structures, collectively called organelles (“little organs”).
- are responsible for specific cellular functions
Nucleus
control centre of the cell and is enclosed. Controls and regulates the activities of the cell (e.g., growth and metabolism) and carries the genes, structures that contain the hereditary information.
nuclear membrane
It allows for movement between cytoplasm & nucleus. separate the chromosomes from the rest of the cell.
cytoplasm
mass of fluid surrounds the nucleus
plasma (cell) membrane
forms the limiting boundary of the cell, separating the cell’s internal environment from the external environment. Selectively permeable barrier that regulates the flow of materials into
and out of cells
mitochondria
involved in the generation of metabolic energy for cellular activity. Produces most of cells ATP
Nucleolus
produces ribsomes
rough endoplasmic reticulum
protein synthesis & transport of proteins for export
smooth endoplasmic reticulum
site of lipid & steroid synthesis and detoxifies drugs
Golgi apparatus
to modify, sort, and package proteins for various destinations in cells
ribsome
involved in protein synthesis
lysosome
digests substances transported into the cell, or digests cellular debris
Centrosome
referred to as the microtubule organizing center (MTOC), is an organelle that regulates the cell cycle via assembly of microtubules. Specifically, spindle assembly is controlled by the centrosome
electron microscope
- light microscope is about 500 times better than that of the unaided eye
- capable of resolving objects about 10,000 times better than the light microscope.
- Heavy metals are used to stain tissue sections increasing the contrast in electron microscopy.
Explain split pea exercise
- To extract DNA
- Why add the dish soap to the split pea solution? Peas have a cell membrane, the dishsoap will help disolve the phosolip membranes in both cell/nucelar membranes. DNA in nucleus is chromatin (DNA wound around histome proteins)
- Meat tenderizers contains a protease which breaks down protein so that we can seperate out DNA
- Then ethanol (all the DNA will enter the ethanol as strands)
