Week 1 (foundations of bio) Flashcards
element
pure substance composed of only one type of atom
matter
any substances in the universe that has mass and occupies space
isotopes
atoms of an element that posses a different number of neutrons
compound
a substance that contains two or more elements
molecule
a group of atoms held together in a particular order through covalent bonds
ionic bonds
bonds between atoms that gain or lose valence electrons completely
covalent bonds
two or more atoms share valance electrons
non polar covalent bonds
equal sharing of electrons for a complete valence shell
polar covalent bonds
-sharing of electrons is NOT equal -leads to hydrogen bonding
-molecules with polar covalent bonds are hydrophilic (water loving)
water cohesion
attraction to other water molecules
(responsible to surface tension)
water adhesion
-attraction to other substances
(water is adhesive to any substances with which it can form hydrogen bonds )
what does water cling to ?
polar molecules
hydrogen bonds
weak attractive forces between hydrogen atoms made partially positive by unequal sharing of electrons
hydrocarbons
consist of carbon and hydrogen
-covalent bonds
-not very soluble in water (non polar covalent bonds )
functional groups(6)
-all water loving
Carbonyl - C=O
Hydroxyl - OH
Carboxyl - COOH
Sulfidryl - SH
Phosphate - PO
Amino - NH2
macromolecules
long molecule built by linking together small, similar subunits
dehydration synthesis
removes OH and H during synthesis of a new molecule (removes water)
hydrolysis
breaks a covalent bond by adding OH and H (adds water)
monosaccharides (simple sugars)
molecules that contain carbon, hydrogen and oxygen
1:2:1 ratio
often form rings
diasaccharides
two monosaccharides joined by a covalent (glycosidic) bond
polysaccharides
made up of multiple monosaccharides
storage polysaccharides
alpha glycosidic bond
-OH pointing down
starch- (plants)
glycogen- (animals)
structural polysaccharides
beta glycosidic bond
-OH pointing up
-cellulose (plants
-chitin (insects)
3 types of lipids
1) Fats
2) Phospholipids
3) Steroids
lipids
molecules insoluble in water
what are fats
-consist of a glycerol molecule with 3 attached fatty acids
-built by dehydration synthesis
saturated fatty acids
in animals
straight link (single covalent bonds/ solids)
unsaturated fatty acids
in plants
double bonds (kinked link/ liquid)
phospholipids
form core of membranes
composed of
-2 fatty acids (hydrophobic)
-glycerol
-phosphate group (hydrophilic)
amphipathic
molecule having both hydrophilic and hydrophobic properties
steroids
-maintains integrity of membranes and membrane fluidity
-act as hormones
polypeptides
amino acids
proteins
nucleic acids
DNA/RNA
nucleotides
amino acids
contain an amino group/ carboxyl group and a hydrogen all bonded to a carbon
peptide bond
links 2 amino acids
polypeptide
when the carboxyl group of a molecule reacts with amino acid group of another molecule releasing water
primary level of structure
linear amino acid sequence
forms foundation of protein shape
secondary level of structure
- alpha helix
- beta sheet
-hydrogen bonding
tertiary structure
3D shape of a single polypeptide molecule
quaternary structure
assembly of several polypeptides
(protein)
chaperones
special proteins that help new proteins fold correctly
denaturation
the unfolding of a protein from its active shape
- results in loss of function
Deoxyribonucleic acid
-encodes info used to assemble -
proteins (no oxygen attached )
-double stranded
ribonucleic acid
-reads DNA-encoded info to direct protein synthesis (has oxygen attached)
-single stranded
nucleic acid structure
composed of long polymers, nucleotides
-5 carbon sugar
-phosphate
-nitrogenous base
nitrogenous bases and their pairs
purines (A &G)
-two rings
-adenine and guanine
pyrimidines (C,T&U)
-one ring
-cytosine, thymine and uracil
pairs
-A/T ( U instead of thymine)
-G/C
which way do strands run
5’ to 3’
2 DNA molecules run in opposite directions
central dogma
DNA-> RNA-> Protein
