Lecture 2 + Chapter 2 Flashcards
What is chemistry?
The study of interactions between atoms and molecules
What is the smallest unit of matter? Can it be subdivided into smaller substabnces
- atom, no
What are molecules?
combinations of atoms forming chemical compund
What are atoms composed of?
electrons
protons
neutrons
What is the atomic mass?
total # of protons and neutron in an atom
What are isotopes?
atoms w/ different # of neutrons
What are the elements of life?
hydrogen
- carbon
- nitrogen
- oxygen
- sodium
- magnesium
- phosphorus
How many electrons can the innermost shell hold?
2 electrons
How many electrons can the second (and possibly third) electron shell hold?
2nd holds up to 8, 3rd can hold up to eight if it is the last/outtermost shell
How many electrons can the 4th, 5th, and 6th shells hold?
Up to 18 electrons
How do Atoms form molecules?
Combining to fill their outermost shells
What is the Valence?
of missing or extra electrons in the outermost shell
How do electron hold together?
Through chemical bonds.
Valence electrons of the combining atoms form attractive forces between the atomic nuclei
What is a compound?
A molecule that contains two or more kinds of atoms
example: H2O
What are the different types of chemical bonds?
Ionic bond
Covalent
Hydrogen
What is an Ionic bond?
Attractions between ions of the opposite charge
What is an Ion?
charged atoms that have gained or lost electrons
What are Cations?
atoms that lose electrons and become positively charged ions
What are anions?
atoms that gain electrons and become negatively charged ions
What is a covalent bond?
when two atoms share one or more pairs of electrons
What is a Hydrogen bond?
when a hydrogen atom that is covalently bonded to an O or N atom is attracted to another N or O in another molecule
What is molecular mass?
The sum of atomic masses in a molecule
What is a chemical reaction?
involves the making or breaking of bonds between atoms
What does endergonic mean?
Reactions ABSORB energy
Define exergonic.
reactions RELEASE energy
What is a synthesis reaction?
occurs when atoms, ions, or molecules combine to form new, larger molecules
What is anabolism?
the synthesis of molecules in a cell
What kind of reaction is this?
A + B —> AB
Synthesis reaction
What is a Decomposition reaction?
when a molecule is split into smaller molecules, ions, or atoms
What is catabolism?
decomposition reactions in a cell
What kind of reaction is this?
AB —-> A + B
Catabolism / Decomp reaction
What is an exchange reaction?
are part synthesis and part decopmosition
What reaction is this?
NaOH + HCI —> NaCI + H2O
Exchange reaction
In what direction does reversing a chemical reaction do?
either anabolism or catabolism
What are organic compounds?
always contain carbon and hydrogen; typically structurally complex
What is an inorganic compound?
typically lack carbon; usually small and structurally simple
What is water?
- inorganic
polar molecule
solvent
hydrogen bonds absorb heat
What is an acid?
Substance that dissociates into one or more hydrogen ions and one or more negative ions
What is a base?
substances that dissociate into one or more hydroxide ions and one or more positive ions
What is a salt?
substances that dissociate into cations and anions
What is pH?
The concentration of H^+ in a solution is expressed as pH
How do you increase acidity?
increase H^+
How do you increase alkalinity?
Increasing OH^-
what pH do most organisms grow in?
between 6.5 and 8.5
What is pH 0-6 considered?
Acidic
What is pH 6.5-8.5 considered?
Neutral
What is pH 9 - 14 considered?
Basic
What do organic compounds usually contain?
hydrogen, oxygen, and/or nitrogen in addition to carbon
Carbon skeleton
chain of carbon atoms in an organic molecule
Functional Groups
bond to carbon skeleton; responsible for chemical properties of a organic compound
Macromules
polymers consisting of many monomers
How do monomers bind?
dehydration synthesis or condensation reactions
Carbohydrates
-cell structures and cellular energy sources
- consist of C, H, and O w/ the formula
- many carbs are isomers
- starch & sugar
Isomer
molecules w/ same chemical formula, just different structures
Monosaccharides
- simple sugars w/ 3-7 carbon atoms
- glucose
Disaccharides
- formed when 2 monosaccharides bond via dehydration synthesis
- can be broken down by hydrolysis
Dehydration synthesis
creation of larger molecules from smaller monomers where a water molecule is released
Hydrolysis
molecule of water breaks down a chemical bond
polysaccharides
10s or hundreds of monosaccharides joined via dehydration synthesis
Lipids
- primary components of cell membranes
- consist of C, H, and O
- nonpolar and insoluble in water
Simple lipids
- fats or triglycerides
Simple lipid: saturated fat
no double bonds in the fatty acids
Simple lipid: unsaturated fat:
one or more double bonds in the fatty acids
cis unsaturated fat vs trans unsaturated fat
cis: H atoms on the same side of the double bond
trans: H atoms on the opposite sides of the double bond
Complex lipids: what do they contain, what are their membranes made of and is it polar or non polar?
- contain C, H and O+P, N, and/or S
- complex lipids called phospholipids
- phospholipids have polar and non polar regions
Steroids
- four carbon rings with an -OH group attached to one ring
- part of membranes that keep the membranes fluid
Proteins: what are they made of and what do they do?
- made of C,H,O,N and sometimes S
- cell structure + function
enzymes speed up chem. reactions
T proteins that move chem. across membranes
Amino Acids
molecules that combine to form proteins
contain an alpha-carbon that has an attched:
- carboxyl group
- amino group
- side group
peptide bond
a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule
Primary structure of the protein structure
it is a polypeptide chain
Secondary structure of the protein structure
when amino acid chain fold and coils in either a helix or pleated sheet
Tertiary structure of the protein structure
when the helix or sheet fold irregularly, disulfide bridges, hydrogen bonds, and ionic bonds btwn amino acids in chain
Quaternary structure
two or more polypeptides
Nucleic Acid
primary information-carrying molecules in cells that consist of nucleotides
Nucleotide
basic building block of nucleic acids DNA and RNA
What do nucleotides consist of?
five carbon sugar
phosphate group
nitrogen containing (purine or pyrimidine) base
Nucleosides
compound commonly found in DNA and RNA, consisting of a purine or pyrimidine base linked to a sugar.
DNA
Deoxyribonucleic acid
contains deoxyribose
In DNA, what does adenine and cytosine bond with?
Adenine - hydrogen bonds w/ thymine
Cytosine - hydrogen bonds w/ guanine
RNA
ribonucleic acid
contains ribose
In RNA, what does adenine and cytosine bond with?
Adenin: hydrogen bonds w/ uracil
Cytosine: hydrogen bonds w/ guanine
Adenosine Triphosphate (ATP): What is it made out of? What does it do?
made of ribose, adenine, 3 phosphate groups
- stores chemical energy released by some chemical reactions
- releases phosphate groups by hydrolysis to liberate useful energy for cell
The number of extra or missing electrons in an atom’s outermost electron shell is called the atoms:
a. atomic number
b. electronic confirguration
c. valence
d. covalence
c. valence
What is formed by the sharing of electrons between atoms to fill an electron shell?
a. isotope
b. ionic bond
c. hydrogen bond
d. covalent bond
d. Covalent Bond
What are the building blocks of protein?
a. monosaccharides
b. amino acids
c. fatty acids
d. nucleotides
b. Amino Acids
What is the difference between an ionic and a covalent bond?
ionic bonds form when two or more ions come together
covalent bonds share electrons between 2 or more atoms
