Lecture 2 - Chemistry Flashcards
Element
a pure substance composed of only one type of atom
Atom
the smallest unit of matter
Describe the Parts of an Atom
Nucleus: Contains Protons & Neutrons
Electron Cloud: Contains Electrons
Name the 3 Subatomic Particles and Their Charges
Protons (+)
Neutrons (neutral)
Electrons (-)
What subatomic particle determines an atom’s identity?
Number of Protons
What are the 6 Most Common Elements in Living Things?
C H O N P S
How many protons, neutrons, and electrons (including valence electrons) are found in Carbon?
Protons: 6
Neutrons: 6
Electrons: 6
Valence Electrons: 4
How many protons, neutrons, and electrons (including valence electrons) are found in Hydrogen?
Protons: 1
Neutrons: 0
Electrons: 1
Valence Electrons: 1
*Note: Wants 2 VE to be Stable
What are ions?
atoms/molecules with a positive or negative charge becauase there are more or less electrons than protons
Molecules
2+ atoms bonded together
Compounds
2+ different types of atoms bonded together
Molecules are formed when electrons are ______ or _______.
Transfered or Shared
Ionic Bonds
oppoSALTSattract
cation with a (+) charge is attracted to an anion with a (-) charge
They do not share elctrons. Electrons are tranferred and then the atoms stay togethr because of their opposite charges.
cation
ion with a positive charge
anion
ion with a negative charge
Describe Covalent Bonds
atoms share electrons with eachother which bonds them together
How many electrons are shared between atoms in single, double and triple bonds?
Single Bond: 2 e- (1 pair)
Double Bond: 4 e- (2 pairs)
Triple Bond: 6 e- (3 pairs)
Which Type of Bond is Stronger? Ionic or Covalent?
Covalent Bonds
Polar Molecules
molecules that have a partial (+) charge on one side and a partial (-) on the other side due to unequal sharing of electrons between atoms in the molecule
Is water a polar molecule? Why or why not?
Yes, water is polar.
Why? Because the Oxygen is an “electron hog” and doesn’t evenly share the electrons with the hydrogens. This results in the O having a partial (-) charge & the H having partial (+) charges.
What is a hydrogen bond?
Hydrogens with partial (+) charges (and bonded to O or N) are attracted to the (-) charges on other molecules.
anabolic reaction
smaller molecules are bonded to synthesize a larger molecule
catabolic reaction
larger molecules are broken down into smaller molecules
endergonic reaction
requires energy
exergonic reaction
releases energy
Organic vs Inorganic Compounds
Organic compounds contain both Carbon and Hydrogen. Inorganic Compounds do not contain both C & H.
What are the 4 Major Types of Organic Compounds?
Carbohydrates
Lipids
Proteins
Nucleic Acids
Explain the pH scale
0-6 Acidic
7 Neutral
8-14 Basic
The concentrations of [H+] and [OH-] are inversely related.
What pH do most organisms grow best in?
pH = 6.5 - 8.5
(close to neutral)
What are buffers used for?
Buffers help stabilize the pH of cultures and keep it from becoming too acidic
turbidity
cloudiness seen in culture mediums that are growing bacteria
Polymers
moleucles made up of several monomers
Dehyration Synthesis
A larger molecule is sythesized and water is released as a product
Hydrolysis
smaller molecules are formed when water is used as a reactant to break apart a larger molecule
-ose
sugar
-ase
enzyme
amphipathic
one end of the molecule is polar and the other end is nonpolar
Describe the Phospholipid Bilayer
Two layers of phospholipids oriented so that the hydrophobic fatty acid tails point towards eachother and the hydrophilic phosphorus heads point outward
Momomers of Proteins
Amino Acids
Describe the Levels of Protein Structures
Primary: strand of amino acids connected
Secondary: alpha-helices and beta-sheets
Tertiary: globular structure
Quaternary: multiple proteins clusered together
denaturing
the breakdown of a protein’s 3D structure caused by temperature, changes in pH, or salt concentration.
Enzymes ______ chemcial reactions.
catalyze
(initiate and speed up)
Exotoxins
toxic proteins produced by bacteria
#disease-causing
What are the 3 parts of a nucleotide?
Phosphate
Sugar
Nitrogenous Base
ribose vs deoxyribose
Ribose has an -OH at the 2’ Carbon and deoxyribose does not
purines
bases with 2 rings
A & G
What are the 2 purines?
A & G
pyrimidines
bases with only 1 ring
C, T, U
nitrogenous bases found in DNA
A T C G
nitrogenous bases found in RNA
A U C G
antiparallel
one strand of DNA runs 5’ to 3’ and the other is upside down and runs 3’ to 5’
What two parts of nuclotides make up the backbone of DNA?
Sugar and Phosphate
What is the Central Dogma?
DNA –> RNA –> protein
DNA
(transcription)
RNA
(translation)
protein
transcription
DNA –> RNA
translation
RNA –> protein
codon
set of 3 consecutive nuclotides in RNA that codes for a single amino acid
ATP
Adenosine Triphosphate
source of cellular energy
ATP –> ADP + P + energy
ADP + P + energy –> ATP
ADP
Adenosine Diphosphate
What type of bond allows capillary action?
hydrogen bonds
What type of bond creates the surface tension of water?
hydrogen bonds
What type of bond holds the two strands of DNA together?
hydrogen bonds
What type of bond forms salt?
ionic bonds
What type of bond forms a single water molecule?
covalent bonds
(*Note: the bonds are polar because Oxygen is an “electron hog”)
What type of bond holds two separate water molecules together?
hydrogen bonds
pH of 2 is how many more times acidic than a pH of 5?
1000x
5-2=3
10^3 = 1000
mono-
one
poly-
many
Dehydration Synthesis AKA
condensation
(because water is released)
hydro-
water
-lysis
breakdown/destruction
lys/o
to kill/separating destruction
What are the 3 main monosaccharides?
Glucose
Fructose
Glactose
saccharide
sugar
What are the 3 major disaccharides?
Sucrose (table sugar)
Lactose (milk sugar)
Maltose
2 Monomers that make Sucrose
Glucose + Fructose
2 Monomers that make Lactose
Glucose + Galactose
2 Monomers that make Maltose
Glucose + Glucose
All 3 major disaccharides contain _________.
Glucose
4 Major Types of Polysaccharides
Starch
Glycogen
Cellulose
Chitin
Glycogen
polysaccharide used to store glucose in the body
Cellulose
polysaccharide used to make the cell walls of plants and most algaes
Chitin
polysaccharide used in the cell walls of most fungi and exoskeletons of lobsters, crabs, and insects
Starch
potatoes
polymer of glucose made by plants and eaten by people
lactase
enzyme that breaks down lactose
(-ase = enzyme)
(-ose = sugar)
Are lipids polar or non-polar?
Non-Polar
Why do oil and water not mix?
Doesn’t mix because water is polar and oil (fat) is nonpolar.
Why does salt dissolve in water?
Salt is polar (held together by ionic bond) and will dissociate in the polar environment of water.
Two Major Functions of Lipids
-plasma membranes
-store energy
If something is hydrophobic, is it polar or nonpolar?
non-polar
4 Classes of Lipids + their Function
- Fatty Acids (fuel)
- Triglycerides (fatty acid storage)
- Phospholipids (plasma membranes)
- Steroids (hormones + strengthen cell membranes)
What is a Triglyceride made of?
1 Glycerol + 3 Fatty Acids
Triglycerides are formed through ______________.
Dehydration Synthesis
Triglycerides are broken down by _______________.
Hydrolysis
Which genus of bacteria produces mycolic acid?
mycobacterium
mycolic acid
a complex lipid found in the cell walls of mycobacterium
Mycoplasma are unique from other bacteria in that they lack a ________.
cell wall
main feature of steroids
4 interconnected carbon rings (3 hexagons + 1 pentagon)
sterol
steroid with an -OH (alcohol) group attached
peptide bond
the bond formed between two amino acids
(the amine group of one amino acid condenses onto the carboxyl group of another amino acid)
What type of reaction of forms a peptide bond?
Dehydration Synthesis
AKA Condensation Reaction because water is released as a product
-OH
alcohol group
-COOH
carboxyl group
-NH2
amino group
-R
indicates any group which has a C or H connectd to the rest of the molecule
oligo-
few
How many amino acids are there?
20
enzymes are ________.
proteins
function of transporter proteins
move/transport molecules across the plamsma membrane that are too big or don’t have the right charge to pass through on their own
bacteriocins
antimicrobial proteins
Difference between DNA & RNA
DNA (DEOXYribonucleic acid) is missing an -OH group at the 2’ Carbon
In DNA, C pairs with
G
In DNA, G pairs with
C
In DNA, T pairs with
A
In DNA, A pairs with
T
In RNA, A pairs with
U
In RNA, U pairs with
A
In RNA, C pairs with
G
In RNA, G pairs with
C
U (uracil) is found in ____ but not in ______.
U is found in RNA, but not in DNA.
T (thymine) is found in ______ but not in ______.
T is found in DNA, but not in RNA.
Which Row is DNA & Which Row is RNA?
GCCGAUCUGCA
CGGCTAGACGT
top row is RNA - we know becase it contains U
Bottom row is DNA - we know because it does not contain U
How is ATP formed?
ADP + P + energy –> ATP
How is ATP broken down?
ATP –> ADP + P + energy
The two strands of DNA are ____ & _____.
Complimentary & Antiparallel
C
Carbon
H
Hydrogen
O
Oxygen
N
Nitrogen
P
Phosphorus
S
Sulfur
Valence Electrons
Electrons in the Outermost Shell/Level of the Atom
What type of bond holds the two separate strands of DNA together?
Hydrogen Bonds
What type of bond allows for Capillary Action?
Hydrogen Bonds
What type of bond create surface tension in water so bugs or leaves don’t sink?
Hydrogen Bonds
Is Water Organic or Inorganic?
Inorganic
Is Carbon Dioxide Organic or Inorganic?
Inorganic
What is a hydrogen ion?
A Lone Proton
CO2
Carbon Dioxide
