CH2 Flashcards
Matter
Physical substance; occupies space and has mass
Mass
- Amount of matter it contains
- Mass is the same when gravity is changed
Weight
An object’s weight is its mass as affected by the pull of gravity
Elements
Substances that cannot be created/broken down by ordinary chemical means;
118 fundamental substances
Chemical Symbol
Each element designated by 1 or 2 letters
Compounds
Two or more elements joined by chemical bonds
Minor Elements
Calcium, phosphorous, potassium, sulfur, sodium, chlorine, magnesium
Atoms
Smallest unit of an element that retains the unique properties of that element
Subatomic Particles
Proton, neutrons and electrons
- The # of protons and electrons within a neutral atom are equal, thus, the atom’s overall charge is balanced
Protons
- Largest particle in atom’s nucleus
- Heavy subatomic particle having a +
charge
(p+)
Neutrons
Heavy subatomic particle having (n)o electrical charge
- In atom’s nucelus
Electrons
- orbits around nucleus
- Subatomic particle having a - charge
- Nearly no mass
(e-)
Electron Shell
Layer of electrons that encircles the nucleus at a distinct energy level; electron cloud
- Holds 8 electrons except the first shell, which can only hold 2
Valence shell
Atom’s outermost shell layer
- Depends on number of electrons in an atom for them to have more than one electron shell
Octet Rule
Atoms are most stable when there are 8 electrons in their valence shell (except hydrogen and helium)
- An atom will give up/gain/share electrons with other atom(s) to have 8 electrons in its own valence shell
Atomic Number
- # of protons in nucleus of an atom
- # above element that is representative of both the number of protons and electrons
Mass Numbers
- # of protons and neutrons in nucleus of atom
- Doesn’t always contain same number of protons and neutrons
Periodic Table of Elements
- A chart identifying elements discovered or synthesized
- Organizes elements according tot heir tendency to react with other elements
Common elements in the human body
- 4 most abundant elements = 96%
1) Oxygen
2) Carbon
3) Hydrogen
4) Nitrogen
Isotopes
Atoms of same element, different # of neutrons
some have same chemical properties but different mass numbers b/c of # of neutrons
Radioactive isotopes
- Elements w/ unstable nuclei or have more than the usual # of neutrons
- Emit radiation from extra energy
-Weak radioisotopes are used in medical diagnostic and treatment procedures
ex: PET scanner - radioactive glucose is injected to detect metabolically active tissues, such as cancerous masses
Molecules
Stable grouping of 2+ atoms held together by chemical bonds
ex: H2(hydrogen gas) or H2O
Compound
When a molecule is made up of 2+ atoms of different elements
Free Radicals
Highly chemically active molecules and ions with an odd # of electrons in their valence shells
- They can form in our body from metabolism of oxygen, food, and/or environmental sources (smoke, sunlight)
- They react with biological molecules like DNA/proteins, and cause cell damage or “oxidative stress”
Acids
Compound that releases hydrogen ions (H+) in solution
Antioxidants
Protects cell membranes from free radical damage
- Sources from food or chemically made in our body (turmeric, avocados, sweet potatoes)
Chemical Bonds
When electrons in atoms valence shell interact with another atom; typically more stable
1) Ionic bonds
2) Covalent bonds
3) Hydrogen bonds
Ion
Atom with overall + or - charge
- An atom can give away or receive one or more electrons
- Loss of (-) electrons = positive charge
- Gain of electrons = negative charge
Cation
Ion with + charge - PAWsitive (cat)
Anion
Ion with - charge - A-Negative
Ionic Bond
- Creates an ionic compound which holds groups of ion’s together by attraction between oppositely charge ions
Ionic Compound
Dissolves in water because water molecules disrupt ionic bonds and release ions = electrolytes
Electrolytes
Minerals in our blood/body fluids that carry electric charge
- Affect amount of water in your body, pH of blood, and nerve and muscle function
Covalent Bonds
These atoms share electrons (do not lose/gain electrons)
- Stronger bond than ionic due to sharing -> does not break in water and can form with the same or different element
Carbon, hydrogen, oxygen atoms are major elements and linked by covalent bonds
Non-polar Covalent Bonds
Type of bond that occurs when two atoms share a pair of electrons with each other
- Single covalent bond: single electron pair (2 electrons) shared b/w 2 atoms
- Double covalent bond: two electron pairs shared b/w 2 atoms
Polar Covalent Bond
Unequal sharing of electrons and hydrogen bonds
Hydrogen Bonds
Bond between two atoms that are involved in other chemical bonds.
- Bond forms b/w partially positive hydrogen atom of a polar molecule and a partially negative atoms (Oz, nitrogen)
- Holds 2 strands of DNA molecule together
Polar Molecule
- Molecules with opposing charges at each end “polar opposites”
Oxidation-Reduction Reactions
One reactant loses electrons (oxidized) while other reactant gains electrons (reduced)
Oxidation
Loss of electrons (OIL)
Reduction
Gain of electrons (RIG)
Catalyst
A substance that increases the rate of a chemical reaction w/o itself undergoing any change
Enzyme
Biological catalyst that speeds up chemical reactions in a cell or body
+ Composed of protein
Inorganic Compounds
A substance that does not contain both carbon and hydrogen
ex: H2O, CO2, sodium NaCl
- Water, salts, acids and bases essential to life
Organic Compound
Contains carbon and hydrogen
Water
Human body made up of 60% of water
- Help us function:
+ Lubrication and cushion
+ Absorbs or dissipates heat for thermoregulation
+ Universal solvent (liquid capable of dissolving another substance
+ Reactant or product of chemical reaction
Acids and Bases
Bother compounds can dissociate in water into charged ions or electrolytes
- Inorganic compounds essential to life
Acids
Release hydrogen ions(H+) in a solution
+ Strong acids dissociate completely, while weak acids do not release all available hydrogen ions
Bases
Releases hydroxyl ions (OH-) in solution or takes up hydrogen ion H+ present in solution
pH
Potential of hydrogen
- Measurement of the concentration of hydrogen ions in solution
- Indicates acidity/alkalinity of a solution
0 = most acidic, 7= neutral, 14= most basic/alkaline
pH scale examples
0= battery acid, hydrochloric acid
2= lemon juice, vinegar
3= grapefruit juice, soda, tomato juice
5= black coffee
6= milk, urine, saliva
7= blood, water
8= sea water
9= baking soda
11= ammonia solution
13= bleach
14= liquid drain cleaner
Buffers
- a solution of a weak acid and its conjugate base that can neutralize small amounts of acids or bases in body fluids.
In our blood, helps to maintain pH levels
Organic compounds in the body
1) Carbohydrates
2) Lipids
3) Proteins
4) Nucleic acids
Carbohydrates
Sugars and starches
- Composed of carbon, hydrogen and oxygen atoms
- Stored in the form of glycogen in liver and muscles
1) Monosaccharides
2) Disaccharides
3) Polysaccharides
Monosaccharides
Building blocks (monomers) of carbohydrates, simplest form
+ mono- = one, saccharide = sugar
+ Glucose, fructose and galactose
Disaccharides
Made by connecting two Monosaccharides
+ Sucrose (table sugar), lactose (milk) and maltose
Polysaccharides
Polymers of monosaccharides; hundreds or thousands of monosaccharides
+ Starches, glycogen, and cellulose - important in body
+ Starch is broken down into glucose (rice, wheat, potatoes)
+ Cellulose is found in the cell wall of plant cells and is a component of fiber
- Our cells use glucose as fuel
- Glucose is broken down to produce adenosine triphosphate (ATP)
Lipids
Mostly composed of carbon and hydrogens, a few oxygen atoms
- B/c they’re rich in carbon and hydrogens, these molecules are non-polar and hydrophobic (does not mix with water)
- Triglycerides, phospholipids, steroids, prostaglandins, fatty acids
Triglycerides
Most abundant lipids in our body and diet (fats and oils)
+ Helps protect, insulate, and provide energy
+ Composed of glycerol and 3 fatty acid chains (via dehydration synthesis)
+ Stored as adipose tissue, highly concentrated fat source
Prostaglandins
- prevents stomach ulcers
- help with inflammation
- dilates airways to lungs
- regulate body temperature
Fatty Acids
Saturated and unsaturated
- fat soluble vitamins: Vitamins D E K
Saturated fatty acids
Doesn’t have double carbon bonds in the carbon chain, solid, or semi-solid at room temp
- butter, lard
Unsaturated fatty acids
Has one or more double carbon bonds, chain shape is kinked
+ Liquid at room temp (olive oil)
Phospholipids
lipid compound in which a phosphate group is combined with a diglyceride.
Important plasma membrane component.
- It’s an amphipathic molecule: has a hydrophobic tail and hydrophilic head
Amphipathic molecules
Chemical compound that has both hydrophilic and hydrophobic parts
Steroids
Has 4 hydrocarbon rings bonded to a variety of other atoms and molecules
- Steroids include sex hormones and cholestorol
Cholestrol
An important steroid and the major component of bile acids
+ Modified to make various steroid hormones in our body
Prastaglandins
Type of of signaling molecules in the body
+ Derived from unsaturated fatty acids, such as omega 3 fatty acids
Proteins
Polymers of amino acids
+ Amino acids are linked by a covalent bond called the peptide bond to form a peptide (short chain of amino acids) or polypeptide (longer chain)
+ Contains nitrogen, carbon, hydrogen and oxygen and frequently contains sulfur
Function of protein in the body
Major components of our cells, tissues, and organs
+ Support - structural proteins (keratin, collagen)
+ Movement - contractile proteins (actin, myosin)
+ Transport - carrier proteins (hemoglobin)
+ Buffering - regulation of pH
+ Metabolism - enzymes
+ Horomones
+ Defense - antibodies
Protein Shape
Primary, secondary, and teritary structures
Primary Structure
Sequence of amino acids in the chain determines overall shape of a protein
Secondary Structures
Alpha-helix and beta-sheet
+ Local structures created by chemical interaction b/w nearby amino acids in a polypeptide chain
Teritary Structure
3D structure of an entire polypeptide chain containing several secondary structures
+ Some protein, such as hemoglobin are formed by multiple polypeptide subunits coming together
Structure/function of protein
Changing protein shapes disrupts functions
ex: heat, pH (denature) –> like cooking an egg
Enzymes
Proteins that catalyze a chemical reaction
+ The reactants in a chemical reaction called substrates, must bind to a specific site called the active site of an enzyme for chemical reaction to take place
+ Shape of active site specifies what substrate can bind to the enzyme
Nucleic Acids
Polymers of nucleotides
- Contain nitrogen, carbon, hydrogen, oxygen and phosphate
- DNA and RNA are examples of nucleic acids
Nucleotides
Adjacent nucleotides are bonded together by phsphodiester bonds to form a chain
Composed of :
- Pentose sugar - either deoxyribose or ribose
- Nitrogen - containing base essential for the replication of genetic material, protein synthesis, and cellular metabolism
+ Either pyrimidine (cystosine, thymine or uracil) OR Purine (adenine or guanine)
Phosphodiester Bonds
A covalent bond that forms the backbone of DNA and RNA
DNA
Deoxyribonucleic Acid
- Genetic material in nucleus of a cell
- Is a polymer of deoxynucleotides which contains deoxyribose, one phosphate group and nitrogenous base (A, C, G or T)
- Double helix formed by two chains (strands) of nucleotides held together by hydrogen bonds between nitrogenous bases of opposite strands
- Hydrogen bonds form between base pairs
+ Adenine-Thymine
+ Cytosine-Guanine
RNA
Ribonucleic acid
- Single strand of ribonucleotides containing ribose, one phosphate group, and one nitrogenous base (A, C, G or U)
Types of RNA
Messanger mRNA
Transfer tRNA
Ribosomal rRNA
ATP
Adenosine triphosphate
- energy carrying molecule found in cells; breakdown of glucose for energy
- releases free energy when its phosphate bonds are broken, and thus supplies ready energy to the cell to do work.
Chemical reactions of physiology
Kinetic, potential, chemical
Kinetic energy
energy of motion, form of energy powers any type of matter in motions, like swimming or running
Potential Energy
energy of position or the energy that matter holds because of the position or structure of its components
Chemical Energy
Chemical bonds between atoms and molecules
- Released by chemical bonds
- When bonds are formed -> chemical energy is invested
- When bonds break -> chemical energy is released
Exergonic Reactions
chemical reactions that release more energy than they absorb; energy EXITs
Endergonic Reactions
chemical reactions that absorb more energy than they release
Mechanical energy
sum of kinetic and potential energy
EX: lifting a brick, muscles provide the mechanical energy to move the brick
Radiant Energy
Energy emitted and transmitted as waves rather than matter
- Varies in length from long radio waves and microwaves to short gamma waves emitted from radioisotopes
- Electromagnetic spectrum
EX: Body uses UV rays from sunlight that’s converted to vitamin D compounded by skin cells
EX: human eye ability to see wavelengths (colors); visible light
Electrical Energy
supplied by electrolytes in cells and body fluids
EX: helps transmit impulses in nerve and muscle cells
Synthesis Reaction
chemical reaction that results in the synthesis (joining) of formerly separate components. (A + B→AB)
Decomposition Reaction
chemical reaction that breaks down or “decomposes” something larger into its constituent part (AB→A+B)
Exchange Reaction
synthesis and decomposition; chemical bonds are both formed and broken, and chemical energy is absorbed, stored, and released (A+BC→AB+C) into chemical bonds
Reactants
one or more substances that enter into the reaction
Products
one or more substances produced by chemical reaction
Factors that influence chemical reactions
Temperature, concentration, pressure (volume of space) *diffusion
Monomers
molecules bond with identical molecules (covalnet bond) to form polymers
Polymers
large molecules made up of many monomers joined together
