Chapter 2 - Chemical Basis of Life Flashcards
Chemistry
the branch of science that studies the composition, properties and interactions of matter
Atomic Number
the number of protons
Mass Number
the total number of protons plus neutrons
Isotopes
atoms with the same atomic number but different mass numbers due to differing amounts of neutrons
Radioactive Isotopes
unstable isotopes that experience atomic degradation which releases energy
- Releases atomic radiation
Forms of Radiation
- Alpha: consists of particles from atomic nuclei which includes two protons and two neutrons which move slowly and cannot penetrate matter
- Beta: consists of electrons(smaller) that travel faster and can more deeply penetrate matter
- Gamma: a form of energy similar to X-radiation and is the most penetrating form of radiation
Octet rule
8 electrons are required to fill the shells in most of the atoms important for living organisms, besides if atoms only have 1 shell
Inert
used to describe atoms who cannot form chemical bonds due to having outermost shells being stable
Ionic Bond
the attraction of two oppositely charged ions which are charged due to the movement of electrons
Covalent Bond
the sharing of electrons between two atoms to fill their valence shells and become stable
Nonpolar Covalent Bond
covalent bonds where atoms are shared equally due to both atoms having similar electronegativity
Polar Covalent Bond
covalent bonds between two atoms where 1 is more electronegative than another, resulting in a pull of electrons towards the more electronegative atom, creating an uneven distribution of charges
Hydrogen bond
he weak polar covalent bond between a hydrogen atom and a oxygen or nitrogen atom
Electrolytes
compounds that ionize in water due to the positive and negative ends in water molecules causing atoms to dissociate
- E.g. sodium chloride in water will dissociate into sodium and chloride ions
- Electrolyte means they can conduct an electrical current in water
Types of Electrolytes
- Acid: substance which releases hydrogen ions
- Base: substances that releases ions which combine with hydrogen ions
- Salt: substances formed by the reaction between an acid and a base
pH Scale
measures H+ concentration in grams of ions per litre from 0-14
- It tracks the number of decimal places in 10 fold differences
- pH less than 7 is acidic due to increase in H+
- pH greater than 7 is alkaline due to Decrease in H+
Blood pH normal levels and disease levels
- Blood pH is between 7.35 to 7.45
- Alkalemia: blood pH above 7.5
- Acidemia: blood pH below 7.3
Alkalosis
a disease someone encounters when their pH of body fluids exceeds above 7.45 making them feel agitated and dizzy
Acidosis
a disease when pH of body fluids decreases below 7.35 making them feel disoriented, fatigued and difficulty breathing.
Buffer
chemical systems which resist pH change by donating H+ when they are depleted or by combining with them when they are in excess
Types of Chemicals in Metabolism
- Organic: molecules which contain both carbon and hydrogen molecules
○ Non electrolytes as they don’t dissolve in water
- Carbs, proteins, lipids, nucleic acids- Inorganic: substances which don’t contain either carbon or hydrogen atoms
○ Usually dissolve in water forming ions(electrolytes)
- e.g. water, oxygen, C02, nitric acid, Carbon Monoxide, inorganic salts
- Inorganic: substances which don’t contain either carbon or hydrogen atoms
Inorganic substances: water
- Most metabolic reactions occur in water as when water dissociates, it turns into ions which are more likely to react
- Water is important in transporting chemicals in the body
○ Blood made up of mostly water, carries oxygen, sugars, salts and vitamins - Water absorbs and carries heat
○ Blood brings heat released from muscle cells to the surface
○ Skin cells secrete water as sweat which releases heat by evaporation
- Water is important in transporting chemicals in the body
Inorganic substances: Nitric oxide
harmful to health yet are important to physiology in small concentrations
- They are biological messenger molecules:
○ NO is involved in digestion, memory, immunity , respiration and circulation
- found in smog, cigarette smoke and acid rain
Inorganic substances: oxygen
- Cells use oxygen to release energy from nutrient molecules
- O2 drives metabolism
Inorganic Substances: Carbon Monoxide
harmful to health yet are important to physiology in small concentrations
- They are biological messenger molecules:
○ CO functions in the spleen recycling old red blood cells and in the brain which controls memory, smell and other functions
- a colorless, odorless gas that is deadly when it leaks from exhaust pipes, home heating systems
Inorganic Substances: Inorganic salts
- The sources of many necessary ions which play a role in metabolism, maintaining water concentration, controlling pH, blood clotting, bone development, energy transfer in cells and muscle and nerve functions
Organic Substances: Carbs
functions:
- Provide cellular energy
- Materials for cell structure
Subunit:
- Monosaccharides
Examples
Organic Substances: Lipids
Functions:
- Provide cellular energy
- Provide structure for membranes
- Assist in hormone synthesis
Subunits:
- Triglycerides:
* 1 glycerol head
* 3 fatty acid tails
- Phospholipids:
* 1 glycerol head
* 2 fatty acids
* 1 phosphate
- Steroids:
* 4 carbon rings
Example:
- oil
- butter
- cell membrane
- cholesterol
Organic Substances: Protein
Function:
- Cell structure
- Transport substances
- Assist in hormone synthesis
- Enzymes
- Movement
Subunits:
- Amino acids:
* Amino group(NH2)
* Central carbon
* R group
* Carboxyl group(CO=OH)
Examples:
- Keratin
- hemoglobin
- Actin/myosin
- Phenalene
Organic Substances: Nucleic Acids
Function:
- Holding genetic code
- Building proteins
Subunits
- nucleotides:
* Deoxyribose sugar
* Phosphate group
* Nitrogenous base
Example:
- DNA
- RNA
Types of reactions:
- Synthesis reaction: building large molecules by bonding smaller ones
- Decomposition: breakdown of large molecules into smaller ones
- Exchange reaction: parts of two different types of molecules trade positions as bonds are broken and new ones are formed
- Decomposition: breakdown of large molecules into smaller ones
