Lecture 2 Flashcards
What are atoms made of? What are their charges?
Protons (+)
Electrons (-)
Neutrons (0)
What does atomic number indicate?
number of protons in the nucleus
What is atomic mass?
of protons and neutrons in the nucleus
What are isotopes?
same proton number, different neutron number
What is the count for electrons in each shell?
2
8
8
What is the outermost shell called? When is it stable? Unstable?
Valence shell
- stable: full or exactly half
- unstable: not full
What are the strengths of the 3 chemical bonds, strongest to weakest?
ionic bond
covalent bond
hydrogen bond
What are ionic bonds?
bond between 2 ions
- OILRIG: oxidation is losing, reduction is gaining
What are covalent bonds?
when electrons are shared between atoms
C-C
C=C
What are hydrogen bonds?
usually between water molecules
- bridge between molecules with hydrogen
What is a synthesis reaction?
2 or more atoms combine to form a larger molecule
A + B -> AB
What is a decomposition reaction?
Bonds are broken to make a larger molecule into smaller ones
AB -> A + B
What is dehydration synthesis?
synthesis reaction where water is released
A + B -> AB + H2O
What is hydrolysis?
H2O is used to break molecules
What are features of inorganic compounds?
Small, simple molecules
- lacks carbon
What are some examples of inorganic compounds?
water, oxygen, salts, acids, bases
What are features of organic compounds?
large, structurally complex
- always has carbon and hydrogen
- covalent bonds
What are examples of organic compounds?
sugars and proteins
What does water do outside the cell?
dissolves nutrients and facilitates passageways
What does water do inside the cell?
facilitates splitting and joining H+ and OH-
What is polarity?
uneven electrical charge between atoms joined by a bond
What is pH?
measure of acidity or basicity of a solution
pH = -log[H+]
What is an acid?
pH 0-6
What can an acid do?
proton donor
- can dissociate into one or more H+
What is a base?
pH 8-14
What can a base do?
proton acceptor
- dissociated into OH-
What are functional groups?
groups of atoms that can bind to the carbon skeleton
What are the 4 major macromolecules?
Carbohydrates
Proteins
Lipids
Nucleic Acids
What are carbohydrates?
2:1 ratio of hydrogen to oxygen
- includes starches, sugars, and cellulose
What are 3 types of carbohydrates?
Monosaccharides
Disaccharides
Polysaccharides
What are monosaccharides?
one carbohydrate
- building block
What is the function of monosaccharides?
quick energy source
- like glucose
What are disaccharides?
2 monosaccharides linked by a glycosidic bond
- covalent bond
What is the function of disaccharides?
Structural component for bacterial cell walls
What are polysaccharides?
large carbohydrate molecule with lots of monosaccharides linked together
What is the function of polysaccharides?
long term energy source (storage) and structural component for plant cell walls
What are proteins?
a bunch of amino acids strung together
What are proteins important for?
essential in cell structure and function
What are some functions of proteins?
- structure
- transporter protein (through membranes)
- enzymes
- antibodies
- bacterial toxins
What are amino acids?
protein subunits
- has alpha-carbon with carboxyl group and amino group
What is a peptide bond?
forms between amino acids through dehydration synthesis
What are the 4 levels of protein structures and how do they differ?
1) Primary - single polypeptide chain/strand
2) Secondary - sequence of polypeptides in helix or sheets
3) Tertiary - pleated sheets folded irregularly with disulfide bridges, hydrogen bonds, and ionic bonds
4) Quaternary - 2+ polypeptide chains bound together
What are lipids?
hydrophobic nonpolar organic molecule
What are the 3 types of lipids?
simple lipids
complex lipids
steroids and sterols
What are simple lipids?
building blocks
What is the function of simple lipids?
Alternative source of energy when carbs aren’t available
What is an example of simple lipids?
Triglycerides: 1 glycerol + 3 fatty acid chains
What are the 2 types of fatty acids?
Saturated: no double bonds
Unsaturated: 1+ double bonds
What is the function of complex lipids?
structure and regulation of transport
What’s the difference between complex and simple lipids?
simple: alcohol + fatty acid
complex: simple + extra molecules
What is a phospholipid made of?
1 glycerol + 2 fatty acid chains + 1 phosphate group
What are the properties of a phospholipid?
Polar (bear) head, nonpolar fatty acid tails
What is mycolic acid?
waxy lipid material in cell wall of Mycobacterium tuberculosis
When are steroids formed?
4 interconnected carbon rings
What is a sterol?
-OH is attached to one of the rings
Why are sterols important?
plasma membranes of animal cells, plants, fungi, and mycoplasma bacteria
- separates fatty acid chains and prevents packing
What are nucleic acids made up of?
5-carbon sugar
Phosphate group
Nitrogen base (either purine or pyrimidine)
What is DNA made of?
Deoxyribose
Sugar-phosphate backbone
Nitrogen bases: A T C G
What is RNA made of?
Ribose
Sugar-phosphate backbone
Nitrogen bases: A U C G
What is the purpose of DNA?
storing genetic information
What is the purpose of RNA?
protein synthesis
What are the purine bases?
Adenine
Guanine
What are the pyrimidine bases?
Cytosine
Thymine
Uracil
What is ATP made of?
Ribose
Adenine
3 phosphate groups
What is the function of ATP?
1) Storing chemical energy release by some chemical reactions
2) Releases phosphate groups by hydrolysis to liberate cell energy
