Flashcards in Chapter 2- Chemical Basis Of Life Deck (104):
The flow of electrons (energy)
Anything that takes up space and has mass
A measure of the amount of matter an object contains
****Stays the same regardless if changes in the objects position****
The measure of how strongly an object is pulled by earths gravity and it varies with distance from earths center
Elements required by life in very minute quantities
Element required by organisms in extremely minute quantities but are TOXIC at high levels (arsenic- Ar)
A pure substance composed of 2+ different elements combined in a fixed ratio (✔️molecule)
Ex: NaCl (sodium chloride)
Smallest possible unit of matter that retains chemical/physical properties of its element
Atoms of the same element share similar chemical properties
Neutrons, Protons, electrons
✔️Two opposites attract each other
✔️Positive attracts negative
What is unique about hydrogen
It has only one electron and one proton, NO neutrons
Where protons and neutrons are found; where mass of entire atoms is measured
Mass of 1 proton, one neutron= 1 Dalton
Where are electrons located
Orbit around the nucleus; held together by electrostatic attraction to positively charged nucleus
Mass so small, it's not used to calculate atomic mass
DETERMINES the atom (unique to each)
Number of protons in an atom
All atoms of an element have the same atomic number (subscripts to the of the elements written symbol)
Number of protons and neutrons in an atom (one of each has mass of approx 1 dalton)
Superscript to left or an elements symbol
1st shell- max 2 electrons
2nd shell- max 8 electrons
3rd shell- max 8 electrons
In what shell do electrons have most energy
The further out the shell, the more energy the electrons have because they aren't being pulled into positively charged nucleus as strongly
Chemical reactions always go to the _________________? energy state
Chemical reactions always go to the LOWEST energy state
Outermost shell is naturally full; ALL gasses (noble gasses)
Atoms of an element that have the same atomic number but different mass number
Different number of NEUTRONS
Under natural conditions, elements occur as mixtures of isotopes
Different isotopes of the same element react chemically in the ____________ way.
Different isotopes of the same element react chemically in the SAME way.
Unstable isotope in which the nucleus spontaneously decays emitting subatomic particles and/or energy as radioactivity
What are two biological applications of radioactive isotopes
1. Dating geological strata (layers) and fossils
2. Radioactive tracers
Trace steps of biochemical reaction or to determine the location of a particular substance within organism
Useful bc they chemically react like the stable isotopes and are easily detected at low concentrations
Cause or cure cancer
Rule that valence shell is complete when it contains 8 electrons
Attractions that hold molecules together
✔️Chemical bonds formed by sharing s pair of valence electrons
Carbon and silicon have 4 valence electrons, what is this called?
Bonding capacity of an atom which is the number of covalent bonds that must be formed to complete the outer shell
The personality of some atoms to be attracted to electrons and pull them close to them!!
EX: N2 and O2 !!!!!!
Uneven distribution of the charge in a molecule
✔️form between molecules or diff parts of a large molecule
✔️Bond formed by the charge attraction when HYDROGEN is COVALENTLY bonded to an ELECTRONEGATIVE atom and is attracted to another electronegative atom
✔️indicated by dotted line in structural formula
Why is DNA hard to unravel?
Bc it has ALOT of weak hydrogen bonds which are strong when together bc there are so many
How many hydrogen bonds can a water molecule form with neighboring water molecules?
What holds DNA together?
Weak hydrogen bonds
A charged atom or molecule
✔️Formed by the electrostatic attraction (positive--->neg.) after the complete transfer of an electron from a donor atom to an acceptor. (Acceptors attract electrons bc electronegative)
✔️strong bonds in crystals not in water (salt dissolves in water bc ionic bonds dissociate into ions
Making and breaking chemical bonds leading to changes in composition of matter; reactants---> products
Matter cannot be created nor destroyed
The relative concentration of reactants and products affects the reaction rate. The higher the concentration the ____________
....greater probability of a reaction
Completion in chemical reaction
All reactants are converted to products. (Majority are reversible)
The RATE of the forward reaction (speed/time) equals the RATE (speed/time) of the reverse reaction
Dynamic- reactions continuing in both directions.
Relative concentrations of reactants/products stay the same
Particles in a mixture are all spread out throughout; mixed together
Dissociation of water molecules
Occasionally, the hydrogen atom that is shared in a hydrogen bond between two water molecules, shifts from the oxygen atom to which its covalently bonded to the unshared orbitals of the oxygen atom to which its hydrogen bonded
What would happen if you took protein (slightly negative charge) and dumped it in acid?
The H+ ions (protons) will all pull the electrons toward them changing the shape of protein thus affecting its function
When does the #H+ = #OH-?
At equilibrium (pure water)
[H+] + [OH-] = ?
M= 10-7 M
Substances that increase the [H+] of a solution; also removed [OH-] bc it combines with H+ to form H2O
Either extremely acidic or extremely alkaline; will burn you
Substances that reduce the relative H+ of a solution; may alternately increase OH-
LEO the lion says GER stands for ?
Lose electrons= oxidation
Gain electrons= reduction
Anything that breaks down into a positive and a negative
Substance formed by the reaction between an acid and a base
1.0 * 10-14
In what pH range are most biological fluids?
6 to 8
Each pH unit represents a ________ difference (logarithmic scale)
Slight change in pH= large change in actual [H+]
Minimizing wide fluctuations in pH to help organisms maintain the Psh of body fluids within the narrow range necessary for life
Prevents sudden changes in pH
Ex: Bicarbonate (buffer in blood)
How do buffers work?
They either donate H+ to the solution when they have been depleted or accept H+ from the solution when they are i know excess
Large molecule consisting of many identical or similar subunits connected together
Ex: protein consists of many amino acids
Subunit or building block molecule of a polymer
Ex: amino acids are the monomers of the polymer protein
Large organic (carbon-containing) polymer
What are the four classes of macromolecules in living organisms
Nucleic acid (DNA,RNA, and ATP)
Chemical reactions that link 2+ small molecules to form molecules with repeating structural units (making a polymer)
Mose polymerization reactions in living things !!!!
(Anabolism) Monomers are covalently linked, producing net removal of a water molecule for each covalent linkage
One monomer loses OH and another loses H
A reactions process that breaks (splits) covalent bonds between monomers by the addition of water molecules
Hydrogen fro water bonds with one monomer and remaining OH from water bonds with adjacent monomer
Ex: digestive enzymes catalyze hydrolysis reactions which BREAK APART large food molecules into monomers that can be absorbed into the bloodstream
Organic (must have carbons and hydrogen to be organic) molecules made of sugars and their polymers
Simple sugars that are monomers or building block molecules in CARBOHYDRATES
Major nutrients for cells ; glucose is most common
Where do carbs store energy
In their chemical bonds and it is harvested by cellular respiration
How do we get energy out of glucose?
Covalent bond formed by a condensation reaction between two sugar monomers
Preferential order of utilization
Body's favorite order of what macros to use first for energy
Carbs --> protein --> fat
Macromolecules that are polymers of a few hundred or thousand monosaccharides
Formed by linking monomers in enzyme-mediated condensation (joining by removing water) reactions
What's the most common storage polysaccharide in animals?
Glucose polymer in animals stored in muscle and liver
Where is glycogen stored in humans?
The liver and muscles
Diverse group of organic compounds that are insoluble in water (hydrophobic) but will dissolve in non polar (like dissolves like) solvents
What are the 3 important groups of lipids
What are fats composed of?
Glycerol- a three-carbon alcohol
Fatty acid (carboxyl acid)- composer of a carboxyl group (COOH) head at one end and an attached hydrocarbon chain (tail)
Hydrocarbon chain (C-H)
Hydrophobic and not water soluble
Bond formed between a hydroxyl group and a carboxyl group
Characteristics of fat:
✔️Insoluble to water
✔️variation among fat molecules is the fatty acid composition
✔️fatty acids in a fat may all be the same or some (all) may differ
✔️ vary in length
✔️ vary in number and location of carbon to carbon double bonds
✔️No double bonds between carbons and fatty acid tail
✔️bonded to MAX number of hydrogens
✔️ solid at room temp
✔️most animal fats
✔️one+ double bonds between carbons in fatty acid tail
✔️liquid at room temp
What are 4 useful functions of fats?
✔️energy storage (one gram stores twice as much energy as a gram of polysaccharide
✔️more compact fuel reservoir (store more energy for less weight than in plants)
✔️cushions vital organs (kidney)
✔️insulated against heat loss
Compounds with molecular building blocks of glycerol, 2 fatty acids, one phosphate group, usually an additional small chemical group attached to the phosphate
How do phospholipids differ from fat?
The third carbon of glycerol is joined to a negatively charged phosphate group instead of another fatty acid
How is a cell membrane's phospholipid bilayer set up?
Has two layers of phospholipids. Each have a hydrophilic head polar head and two hydrophobic fatty acid nonpolar tails. The heads are facing outward toward extra|intra cellular areas and tails are facing inward
Lipids which have 4 fused carbon rings with various functional groups attached
Ex: cholesterol is important steroid
Very important steroid
✔️adds stability to cell membrane (adds viscosity (thickness) to membrane)
✔️precursor to many other steroids (sex hormones etc)
Characteristic of cell membrane to move
Fluid- move all around
Mosaic- all different components
Polymer of amino acids
Structure of amino acids
Carboxyl end (COOH) and an amino acid end (NH2) as well as a variable R group
2+ amino acids
Formed between the amino group (NH2) of one amino acid to the carboxyl group (COOH) of the next
How many kinds of amino acids are use in protein structure?
What are the four levels of protein structure?
The order of the amino acids in a peptide
Coiled or FOLDED shape held together by hydrogen bonds
Further bending and folding
Between 2+ peptide chains
Will protein dissolve in water? Why/why not?
Yes bc proteins is polar and water is polar. Like dissolves like. The protein will bend on itself until is bonds with hydrogen in H2O
✔️Overall protein shape
✔️Cannot function properly if shape is altered
An unraveled or destroyed protein
Occurs when heat or changes in pH change protein shape