All of Chapter 1 Flashcards
Chapter 1
Atoms have what at their core?
A nucleus at their core and are surrounded by electrons
- a nucleus is composed of protons and neutrons
Atomic number
Number of protons in the nucleus of an atom
Protons, neutrons, electrons
Protons: positively charged, Neutrons: no charge, Electrons: negatively charged
Mass number
Number of protons and neutrons in the nucleus
Neutral atoms may have diff # of neutrons, and are known as what?
Isotopes
- Ex. Carbon-12, Carbon-13 (1 xtra neutron), Carbon-14 (3 xtra neutrons)
What are isotopes?
Element that has the same # of protons, or atomic number, but a diff # atomic mass cuz of the change in neutron number!
- most isotopes r stable but decay over time
What are radioactive isotopes/radioisotopes?
Has a unstable nuclei that break apart: radioactive - subatomic particles are released as well as some radiation
What are valence electrons?
Electrons involved in bonding btw atoms
- possess the highest energy (outermost electrons)
Common uses for radioisotopes? 4 uses
C-14: carbon dating, tracing cancer
Ca-45: measures bone formation rate
K-40: fossil dating
Ra-226: cancer treatment
Intermolecular bonds
Bonds formed between atoms and interaction of valence electrons
- ionic
- covalent
- polar covalent
What are core electrons?
Electrons when under normal reaction conditions are chemically inert
Ionic bonds
Exchange or transfer of electrons from one atom to another
- bonding makes atoms more stable
- opposite charges attract each other
Covalent bond
Sharing of electrons.
- valence electrons are shared between atoms. usually 2 nonmetals
What are the 4 main types of biochemical reactions?
- Acid-base/ Neutralization Reaction
- Acid-Base Buffer Reactions (not rlly apart of it)
- Redox Reaction (Oxidation, Reduction)
- Hydrolysis and Condensation (dehydration synthesis) reaction
Biomolecules
covalent bonds give structure to biomolecules, and non-covalent bonds give dynamics
- Ex. phosphodiester bonds in DNA give structure to DNA & act as a backbone
- Ex. ionic bonds, hydrogen bonds in protein folding
What are the 4 major macromolecules
- Carbohydrates
- Lipids (Fats)
- Proteins
- Nucleic Acids
What forms the backbone of biomolecules, and forms covalent bonds with metals
Carbon
Polymerization
Creates richness of life - holds the molecules
Aqueous Solutions (aq)
Can be classified as either acidic, basic, or neutral
Acidic Solutions
High concentration of Hydrogen Ions (H+)
Basic Solutions
High concentration of hydroxide ions (OH-)
Neutral Solutions
Have an equal amount of hydrogen and hydroxide ions
Inorganic
Carbon molecules not bonded with hydrogen
Organic
Carbon molecules bonded with hydrogen
Most of the biosphere is composed of..
Carbon, Hydrogen, Nitrogen, Oxygen
Hydrocarbons
Made of only carbon and hydrogen
Ex. methane, ethane, propane (generally non-polar because of low electronegativity)
Pure water undergoes what?
Autoionization, where 2 water molecules in every 550 mill reaction with each other to produce a hydronium ion (H3O+) - acidic, and a hydroxide ion (OH-) - basic.
Functional groups and what r the 6 ones?
Handles that stick out on biomolecules exhibit particular chemical properties and account for an organic molecule’s reactivity
ex. carboxyl + amino –> peptide bond
- hydroxyl
- carbonyl
- carboxyl
- Amino
- Phosphate
- Sulfhydryl
Intermolecular bonds
interactions btw molecules that hold 2 or more molecules to one another. much weaker then intramolecular bonds
London Dispersion forces
Weak forces of attraction between all atoms and molecules.
Dipole-Dipole Forces
Hold polar molecules together. stronger than london forces
Hydrogen Bonding
Very strong dipole-dipole forces that form between the electronegative H of one polar molecule and the electronegative N, O, or F of another.
Water molecules are held together by..
Hydrogen bonds. which are actually forces between molecules and not true bonds
- due to the polar covalent bonding within each molecule, water will have a positive and negative pole attracting each other.
Water is a solvent and dissolves substances easily, why?
It’s because of the polarity.
- when ionic solids dissolve, the anions and cations dissociate (ionic bonds are broken)
Insoluble
Substances that cant dissolve in water
Hydrophilic
If a substance is polar, it will dissolve in water and form hydrogen bonds
Ex. salts
Hydrophobic
If a substance is nonpolar, it will not dissolve in water, nor form hydrogen bonds
Ex. fats and oils
prop of water: Cohesion
Water molecules form hydrogen bonds with one another
effect: High surface tension
prop of water: Adhesion
Water molecules form hydrogen bonds with other polar materials
Effect: capillary action causes water to creep up a narrow glass tube and paper.
Ex. Transpiration
prop of water: High density at 4°C
Below 0°C, water molecules form a crystalline lattice. H-bonds spread apart, low density.
Effect: ice floats on liquid water allowing for aquatic life in winter
prop of water: High Specific Heat Capacity
Hydrogen bonding causes water to absorb much heat before its temp. increases & also causes it to lose huge amounts of heat before its temp. decreases
Effect: temperature moderation. Helps organisms maintain a constant body temperature
prop of water: High Specific Heat of Vaporization
Hydrogen bonding causes liquid water to absorb a large amount of heat to become a vapor (gas)
Effect: evaporation cooling. Allows for organisms to dissipate body heat by evaporation from skin and tongue
acid is a proton donor or acceptor?
proton donor
base is a proton donor or acceptor?
proton acceptor
Polar Functional Groups
Alcohols (-OH) and Carboxyls (-COOH) are polar due to the electronegative Oxygen. so sugars and alcohols are very soluble (hydrophilic) in water since they have polar hydroxyl groups