2 lecture 2 Flashcards
what are The properties of water (H2O) aka hydrogen bonds
as a liquid, the H-bonds between H2O molecules break continuously but randomly
fluidity over a large temp range, mixes molecules for chemical reactions, moderates temperature, surface tension (cohesion)
individual water molecules are weak, many together are strong
ionic bonds more likely to break than covalent bonds true or false
true
polar water molecules dissolve the salt into what
Na+ and Cl- ions
what does hydrophilic mean
tend to “stick together” tend to like to e in an aqueous solution
what does hydrophobic mean
cannot dissolve in water does not like water
do Polar molecules (like H2O) tend to be hydrophilic or hydrophobic
hydrophilic
what does it mean by; Polar molecules (like H2O) tend to be hydrophilic.
Substances that are charged/polar o[en dissolve in water due to hydrogen bonds
Nonpolar molecules (like CO2) are called hydrophobic or hyrophillic
hydrophobic
what does it mean by; Nonpolar molecules (like CO2) are called hydrophobic
because they tend to aggregate with other nonpolar molecules in water
what are the different types of interaction
1) hydrophilic interaction (attraction; polar to polar)
2) hydrophobic interaction (attraction; non-polar to non-polar)
3) repulsion
weak forces (collectively called Van der Waals interacTons) are very important in large what
molecules (proteins, lipids etc.)
what is an acid
acids release H+ ions
If the reaction (dissociation) is complete, it is a strong acid, such as HCl
Bases accept____ (release _____).
H+, OH–
what is pH:
H+ in moles* per liter
what is the pH range
pH range of 1 - 14
molecules interact to form what
larger macromolecules and cells
carbon is what kind of atom
a “Tinkertoy” atom
why is carbon known as a tinkertoy atom
incredibly flexible - used to build many types of complex macro molecules
many molecules are______ with repeating______
biological polymers, subunits
carbohydrates are a source of what
energy
example; glucose
polysaccharides form what
rigid biological structures such as hard shells of bugs
what is a Disaccharide
and of class of sugars whose molecules contain 2 monosaccharide residue
what is an example of a Disaccharide
sucrose– glucose + fructose
what are amino acids and polypeptides
the basic unit, or monomer
not typically repeating units
how do you form a polypeptide
add monomers ate the amino end to form a polypeptide
what makes the amino acids different than each other,
R
are amino acids an acid or a base
amino acids are both an acid and a base
polypeptide of three amino acids linked by what
polypeptide of three amino acids linked by peptide bonds
proteins are composed of many what
amino acids
for the structure of amino acids, what is the same
the top parts are identical
are amino acids polar or non polar
there are both
what are the key concepts to identifying non-polar amino acids (proteins)
amino acids have a hydrocarbon side-chain (e.g. alanine; -CH3)
exception: glycine; -H
sometimes uncharged
what are the key concepts to identifyingpolar amino acids (proteins)
have side chains with partial charge or net )+) charge or net (-) charge
(basically has a little + or = at the one of the bottom chains or is OH)
a protein is a folded_____
polypeptide
what is an r-group
side chain
difference between a protein and a polypeptide?
protein— folded version of polypeptide, active
polypeptide— chain of amino acid, don’t have to be active
the shape of the folded protein is encoded in what
the polypeptide sequence
what are Lipids
fats
steroids
phospholipids
what is a fat
a fat is a simple 3-carbon lipid
has 3 fatty acid tails and is hydrophobic
what are phospholipids
a lipid containing phosphate group in its molecule
what are the characteristics of a phospholipid
2 fatty acid tails (hydrophobic)
charges phosphate head (hydrophilic)
the dual properties of phospholipids allow them to form what
barriers
how do that barriers formed by phospholipids work
tails stay in the middle and the heads are on the outside
large charged molecules can’t get through because they will encounter the tails and just wont be able together through
in an aqueous environment
dispersed among the heads and tails are proteins (as seen in this picture)
what some of these proteins do is act as channels that move things through
the membranes of phospholipids form what kind of barriers
fluid, semi-permeable barriers
what parts of the barrier are hydrophobic and what parts or hydrophillic
tails– hydrophobic
heads– hydrophillic
what do steroids do
help to keep membrane fluid and move
a steroid is composed of what
four carbon rings (6 or 5 carbons)
what is DNA
Nucleic acids (DNA)
what are the 4 bases of DNA
A (adenine)—
G (guanine)—
T (thymine) —
C (cytosines)—
which bases of DNA are pyrimidines
T (thymine) — pyrimidines
C (cytosines)— pyrimidines
which bases of DNA are purines
A (adenine)— purines
G (guanine)— purines
what does it mean by DNA is a doble helix
two strands linked together
individually, is DNA strong or weak
individually, the DNA is very weak, but this means for an easy replication of DNA, but together it is VERY strong
what is The Pairing rule of DNA
AT
CG
purines and pyrimidines
what is The structure of a DNA molecule
anti-parallel strands of repeating subunits
what is the backbone” of DNA
phosphate + sugar (covalent bonds)
are the AG and TC pairings covalent or hydrogen
hydrogen
what are the 2 types of cells
Eukaryotic vs prokaryotic cells
what is the cell theory
Cells are the smallest independent units of life
All living things are made of cells
Cells are formed by the reproduction of existing cells
what all cells have in common
a plasma membrane cytoplasm DNA RNA proteins ribosomes (rRNAs and proteins)
what are the traits of prokaryotic cells
are- generally small <1 μm (1/10 the size of a small eukaryotic cell) no nucleus few internal membranes never multicellular cell wall made of peptidoglycan some are- aerobic (use oxygen), or anaerobic (don’t use oxygen)
traits of eukaryotic cells
are- larger than bacteria ~ 5-25 μm has a nucleus many internal membranes membrane-based organelles unicellular or multicellular cell walls- depends on kingdom all are aerobic (use oxygen)
difference between plant and animal cells
plant cells have a central vacuole, cell walls and chloroplast
