Chapter 2: Chemistry Comes Alive Flashcards
Matter
Anything that occupies space and has mass
Energy
The capacity to do work, or to put matter in motion
Kinetic Energy
Energy in action
Potential Energy
Stored energy
What is the connection between matter and energy?
They are inseparable; Matter is substance and energy is the mover of the substance
Chemical Energy
The form stored in the bonds of chemical substances
1) Atoms rearrange
2) PE is released
3) KE
Describe Eating
1) Food E is captured temporarily in the bonds of a chemical called ATP
2) ATP bonds are broken, PE is released for cellular work
Electrical Energy
Results from the movement of charged particles
- Electrical currents (ions move across cell membranes)
- Nerve impulses
- Pumping blood
Mechanical Energy
Energy directly moving matter
Radiant Energy/ Electromagnetic Radiation
Energy that travels in waves
Electromagnetic Spectrum
Waves that are varied in length
Energy Conversions
- Energy can easily convert
- Inefficient: Initial energy is always “lost” in the environment as heat (unusable energy)
- All conversions give off heat: helps with homeostasis
Elements
Unique substances that cannot be broken down into simpler substances by ordinary chemical means
Atoms
Identical particles or building blocks of elements
Physical Properties
Those we can detect with our senses or measure
Chemical Properties
Pertain to the way atoms interact with other atoms
Nucleus
(1) Control center of a cell; contains genetic material; (2) center of an atom; contains protons and neutrons
Protons
Positive electrical charge
Neutron
Neutral, so nucleus is positive overall
What are the connections between protons, neutrons and the nucleus
1) Protons and neutrons are heavy subatomic particles of the nucleus
2) Nucleus is dense= 99.99% mass of the atom
Electrons
Negative charge equal in strength to the positive charge of the proton
What are all atoms charged?
Neutral; the # of protons in an atom is balanced by its # of electrons
Planetary Model
A simplified model of atomic structure
Orbital
Regions around the nucleus in which a given electron or electron pair is likely to be found most of the time
Orbital Model
More useful for predicting the chemical behavior of atoms
- predicts probable regions of greatest electron density by denser shading (electron cloud)
Atomic number
Equal to the # of protons (electrons)
Mass number
The sum of the masses of its protons and neutrons
Isotopes
2 or more structural variations of elements that have the same # of protons and electrons but a different # of neutrons
Atomic Weights
An average of the relative weights of all the isotopes of an element
- Atomic # = Mass # of most abundant isotope
Radioactivity
The process of atomic decaying spontaneously into more stable forms because of unstable heavier isotopes
Radioisotopes
Isotopes that exhibit radioactivity
Quarks
Smaller particles of the nucleus that associate one way to form protons and another neutrons
- holds nuclear particles together and is weaker in heavier isotopes
Molecule
A combination of 2 or more atoms of the same element held together by chemical bonds
Compound
2 or more different kinds of atoms bind, they form molecules of a compound
- Chemically Pure
- Identical Molecules
Mixtures
Substances composed of 2 or more components physically intermixed
What are the 3 basic types of mixtures?
1) Solutions
2) Colloids
3) Suspension
Solutions
Homogeneous mixtures of components that may be gases, liquids or solids
- Particles are very tiny
- Do not settle
- Scatter light
Solvent
The substance in the greatest amount (or dissolving medium)
- Usually liquid
Solute
Substances present in smaller amounts (dissolved in the solvent)
True Solutions
Contains gases, liquids or solids dissolved in water
- Usually transparent
- Ex: Saline Solution, Mix: Glucose/ Water, and Mineral Water
- Solutes are minute
- Do not settle out/ scatter light
How do you describe True Solutions?
By their concentration
- College/ Hospital: percent (parts per 100 parts) of the solute in the total solution (water is the assumed solvent)
- Blood Concentration: Milligrams per deciliter
- Molarity
Molarity
Moles per liter, M
- Complicated but useful
Mole
Equal to any element or compounds atomic weight or molecular weight
Molecular weight
Sum of atomic weights
Avogadro’s Number
6.02 X 10(23)
Colloids/ Emulsions
Heterogeneous mixtures
- Translucent/ Milky
- Large particles
- Scatter light
- Do not settle
Sol-gel Transformation
To change reversibly from a fluid (sol) state to a more solid (gel) state
- Ex: Jell-O
• Underlie important cell activities
Suspensions
Heterogeneous mixtures
- Very large particles
- Often visible solutes that settle out
- Ex: Blood
What are the differences between mixtures and compounds?
1) No chemical bonding in mixtures (only physically intermixed)
2) Mixtures can be separated by physical means
Compounds—> Chemical means
3) Mixtures: Homogeneous/ Heterogeneous
Compounds: Homogeneous
Chemical Bonds
An energy relationship between the electrons of the reacting atoms
Electron Shells
The regions of space of an atom around the nucleus where electrons are forming an electron cloud
Valence Shell
An atoms outermost energy level containing the electrons that are chemically reactive
What are the 3 major types of chemical bonds?
1) Ionic
2) Covalent
3) Hydrogen
Ions
Charged particles that form when the balance of + and - are lost
Ionic Bond
A Chemical bond between atoms formed by the transfer of one or more electrons from one atom to another
Electron Acceptor
The atom that gains one or more electrons
Anion
The negative net charge in an electron acceptor
Electron Donor
The atom that loses its electrons
Cation
A positive net charge in an electron donor
Describe an Ionic Bond
Both anions and cations are formed whenever electron transfer between atoms occur. Opposite charges attract so these ions tend to stay close together= Ionic bond
Crystals
Large arrays of cations and anions held together by ionic bonds
Covalent Bond
Electrons sharing produces molecules in which the shared electrons occupy a single orbital common in both atoms
What are the 2 types of molecules in covalent bonds?
1) Polar
2) Non Polar
Non Polar molecule
Equal sharing of electrons
- Don’t have separate + and - poles of charge
Polar molecule
Unequal sharing of electrons
Electronegativity
Electron hungry and attract electrons very strongly
Electropositive
Atoms with only 1 or 2 valence electron shells
- Potassium
- Sodium
What is another name for a polar molecule?
Dipole
Hydrogen Bonds
When a hydrogen atom, already covalently linked to one electronegative atom, is attracted by another electronegative atom, so that a “bridge” forms between them
Chemical Reaction
Occurs whenever chemical bonds are formed, rearranged or broken
Subscript
Indicates that atoms are joined by chemical bonds
Prefix
Denotes the # of unjointed atoms or molecules
Reactants
The # and kinds of the interacting substances
Products
The chemical composition of the result of the reaction
Relative Proportions
Balanced equations indicated the relative proportion of each reactant and product
Molecular Formula
Representation of a product in a molecule
Synthesis/ Combination Reaction
Involves bond formation
A + B—-> AB
Anabolic(sm)
Energy requiring building phase of metabolism in which simpler substances are combined to form more complex substances
Name an example of synthesis reaction
Amino acids are joined together to form a protein molecule
- smaller particles of bonded together to form larger, more complex molecules
Decomposition Reaction
Occurs when a molecule is broken down into smaller molecules
AB—-> A + B
- Reverse Synthesis
Catabolic(sm)
Process in which living cells breakdown substances into simpler substances
Exchange/ Displacement Reaction
Involve both synthesis and decomposition bonds of both made and broken. An exchange reaction occurs when ATP reacts with glucose and transfers it end phosphate group to glucose forming glucose phosphate at the same time, the ATP becomes ADP this important it reaction occurs whenever glucose into the body cells and is effectively traps the glucose fuel molecule inside the cell
Oxidation-Reduction/ Redox Reaction
Decomposition reactions in that they are the basis of all the actions in which food fuels all broken down for energy (ATP). Electrons are exchanged between the reactants. The reactant losing that electrons is the electron donor and is said to be oxidized. The reactant taking up the transferred electrons is the electron acceptor and it said to be reduced
Exergonic Reactions
Reactions that release energy. These reactions yield products with less energy than the initial reactants along with energy that can be harvested for other uses with few exceptions catabolic and oxidative reactions on exergonic
Endergonic
The products of energy absorbing. Contain more tensional energy in the chemical bonds than did the reactants
- Ex: Anabolic Reactions
What is the reversibility represented in a chemical reaction?
Double arrows
- when arrows differ in length the longer arrow indicates the major direction in which the reaction proceeds
- when the arrows are of equal length, the molecule of the product forms one molecule, breaks down releasing the reactants A & B. This chemical reaction is in a state of chemical equilibrium
What happens when the chemical equilibrium is reached?
There is no for the net change in the amounts of reactants and products unless more of either are added to the mix
What factors influence the rate of chemical reactions?
1) Temperature
2) Concentration
3) Particle Size
4) Catalyst
Temperature
Increasing the temperature of a substance increases the kinetic energy of its particles and the force of their collisions
Concentration
Occurs when the reacting particles are present in high numbers because the chance of successful collisions is greater. As the concentration of the reactants declines, the reaction slows. Chemical equilibrium eventually occurs.
Particle Size
Smaller particles move faster than larger ones and tend to collide more frequently and more forcefully
Catalysts
Substances that increase the weight of chemical reactions without themselves becoming chemically changed or part of the product
What are biological catalysts called?
Enzymes
Biochemistry
The study of the chemical composition and reactions of living matter
What 2 Major categories do the chemicals in the body fall into?
1) Organic
2) Inorganic
Organic Compounds
- Contains carbon
- Covalently bonded
- Many are large
Inorganic Compounds
All other chemicals in the body (not carbon)
- Ex: Water, Salts, many acids and bases
What are the 5 properties of water?
1) High Heat Capacity
2) High Heat of Vaporization
3) Polar Solvent
4) Reactivity
5) Cushioning
High Heat Capacity
Absorbs and releases large amounts of heat before changing appreciably in temperature itself.
Prevents sudden changes in temperature caused by external factors or by internal conditions that release heat rapidly
- External: Sun, Wind Exposure
- Internal: Vigorous muscle activity
Redistributes heat among body tissues ensuring temperature homeostasis
High Heat of Vaporization
When water evaporates it requires large amounts of heat being absorbed to break the hydrogen bonds that hold water molecules together
- Ex: Perperation
Polar Solvent
Because water molecules are polar they orient themselves with their slightly negative and toward the positive ends of the solutes and vice versa first attracting the solute molecules and then surrounding them. This polarity of water explains why ionic compounds and other small reactive molecules dissociate in water there ions separating from each other and becoming evenly scattered in the water forming to solutions
What are the water molecule layers called?
Hydration layers
Hydration Layers
Forms layers around large charged particles, such as proteins shielding them from the effects of other charged substances in the vicinity and preventing them from settling out of solution
What are protein-water mixtures called?
Biological Colloids
- Ex: Blood plasma, cerebrospinal fluid
Reactivity
Water is an important reactant in many chemical reactions
Cushioning
By forming a resilient cushion around certain body organs, water helps protect them from physical trauma
Salt
An ionic compound containing cations other than H+ and anions other than the hydroxyl ion (OH-)
What happens when salts dissolve into water?
They dissociate into their component ions
- Ex: Sodium Sulfate, Na2SO4—-> 2 Na+ ions and 1 SO4 2- ion
Electrolyte
Substances that conduct an electrical current in solution
Polyatomic ions
Groups of atoms that bear and overall charge (Ex: Sulfate)
What are the most commonly found salts in the body?
- NaCl
- CaCO3 (calcium carbonate)
- KCl (Potassium Chloride)
Acids
A substance that releases hydrogen ions in detectable amounts
- Proton Donor
- Sour taste
- can react with (dissolve) many metals
- Ex: Acetic Acid (HC2H3O2/ HAc), carbonic acid (H2CO3)
- The hydrogen is always first in an acidic molecule!!!!!
Proton Donor
When a hydrogen ion is just a hydrogen nucleus
What determines the acidity of a solution?
The concentration of protons
Bases
- Bitter taste
- Feel slippery
- Proton acceptors
- Inorganic bases: Hydroxides
Proton Acceptors
Take up hydrogen ions (H+) in detectable amounts
Hydroxyl ions
Ions liberated when a hydroxide is dissolved in water
Bicarbonate ion (HCO3-)
An important base in the body, particularly abundant in blood
Ammonia
A common waste product of protein breakdown in the body (also base)
It has 1 pair of unshared electrons that strongly attracts protons
By accepting a proton, ammonia becomes an ammonium ion
NH3 + H+ —–> NH4+
pH units
The concentration units used to measure the relative concentration of hydrogen ions in various body fluids
Who created the pH scale?
Danish biochemist and beer brewer Sören Sörensen in 1909
Neutralization Reaction
When acids and bases on mixed, because the joining of H+ and OH- form water neutralizes the solution
Buffers
The chemical systems of homeostasis that regulates acid-base balance
Hydroxyl
-OH
Carbonyl
=aldehydes; ketones
Carboxyl
-COOH
carboxylic acids
Amino
-NH2
amines
Sulfhydryl
-SH
thiols
Phosphate
-PO4
organic carbohydrates
Dehydration Reaction
Process by which a large molecule is synthesized by removing water and covalently bonding smaller molecules together; water splitting 2 molecules
Hydrolysis
Process in which water is used to split a substance into smaller particles; water leaves causing a junction
Monomer
1 subunit
Polymers
Many subunits
What is the major function of Carbohydrates?
Immediate energy source; some structural support
What are the major functions of a Protein?
1) Structure
2) Signaling (hormones)
3) Enzymes/ Catalysts
4) Transport
Enzymes
- Substrate specific
- Denatured by heat, pH extremes, chemicals, electricity, radiation
What do Proteins contain?
- An amino and carboxyl group
* Peptide Bonds
What are the Macromolecules of Carbohydrates?
- Disaccharides (sucrose)
- Polysaccharides (starch, glycogen)
What are the major functions of Lipids?
1) Cell membrane
2) Insulation
3) Nerve transmission
4) Energy Reserve
Saturated Fats
- All single bonds
* Animal products
Unsaturated Fats
- Double or triple bond
* Plant products
What is the major function of Nucleic Acids?
Determines the synthesis of proteins; control the cell (information)
DNA
Deoxyribonucleic acid • Double strand • Sugar: Dioxyribose • Bases: Adenine, Thymine, Guanine, Cytosins • Carries instructions to make proteins • Permanent
RNA
Ribonucleic acid • Single strand • Sugar: ribose • Bases: Adenine, Uracil, Cytosine, Guanine • Works to make the proteins • Temporary
What are the building blocks of Organic Phosphates?
Adenine and Phosphate
What is the major function of Organic Phosphates?
Cell’s energy molecule
When are Organic Phosphates made?
Cellular Respiration
