Core Concepts, Water and Chem of Life
What is a covalent bond?
when two atoms share one or more pair of valence electrons
What is the monomer of a protein and a carb?
protein: amino acid
carb: monosaccharide
Name the nucleotides and what the pair with
A-T
G-C
A-U
What is the difference between saturated and unsaturated?
saturated: no double bonds between carbon atoms= as many hydrogen atoms as possible
unsaturated: 1 or more double bonds between carbon
This model describes the membranes as a dynamic mixture of lipids and proteins that move laterally within the later
fluid mosaic model
What is an emergent property? (lo 2.2)
Each level of organization has emergent properties.
• Results from interaction of components.
• Cannot be deduced by looking at parts themselves.
• “Life” is an emergent property.
What are the functions of proteins in the cell?
1. Enzyme catalysis - enzymes facilitate specific
chemical reactions
2. Defense – against invaders/recognize self
3. Transport – small molecules and ions
4. Support/Structure - collagen
5. Motion – muscle contraction
6. Regulation - hormones; control of gene
expression
7. Storage – ion-binding (iron, calcium)
List the components of a nucleotide
5 carbon sugar
phosphate group
nitrogenous base
What would happen if you drop a phospholipid bilayer into water?
It would form a micelle
A small, nonpolar molecule like O2 moves directly through the phospholipid bilayer from high to low concentration without a protein. What kind of movement is this?
simple diffusion
What is a hydrogen bond? give me an example
An attraction between a partial positive charge on a hydrogen atom and a partial negative charge on another atom.
ex: a water hydrogen bonding with another water
What makes up an amino acid?
central carbon, carboxyl group, amino group, r group
true or false: the two dna strands run parallel to each other
false, they run anti parallel
What does amphipathic mean?
have both hydrophobic and hydrophilic regions
Glucose moves into a cell down its concentration gradient by binding to a membrane protein that changes shape but does not use ATP. What kind of movement is this?
Facilitated diffusion (via a carrier protein)
List the 7 Characteristics of life (LO 2.3)
1. cell org
2. ordered complexity
3. sensitivity to environment
4. growth, development and reproduction
5. energy untilization
6. homeostasis
7. evolutionary adaptation
What are the 4 structures of a protein and describe/ draw what they look like
primary- single chain of amino acids
secondary- alpha beta and pleated sheets
tertiary- r group interactions
quaternary- many subunits of proteins come together to form 1
List the 4 differences of dna and rna
dna: deoxyribose, agct, h at 2', double stranded
rna: ribose, acgu, oh at 2', single stranded
Why is a phospholipid amphipathic?
has a hydrophilic, polar head and hydrophobic, nonpolar tails
The type of transport moves substances from low to high concentration using ATP and often involves carrier proteins such as pumps
active transport
What is electronegativity? How does it influence the electron position in a covalent bond? How does it influence the partial charges on atoms in a covalent bond?
Defined as an atom’s affinity for electrons
Differences in electronegativity dictate how
electrons are distributed in covalent bonds
– Nonpolar covalent bonds = equal sharing of
electrons
– Polar covalent bonds = unequal sharing of
electrons. Electrons are not shared equally (ex: O is more electronegative than H), so partial charges exist on the O and H atoms.
describe the different types of bonds that are in the different structures of proteins
1. primary- peptide bonds
2. hydrogen bonds between the amine and carboxyl groups in peptide backbone
3. interactions between r groups: h-bonding, hydrophobic interactions, di-dulfide bridge, ionic bonds
what is the complementary strand of DNA:
5' AGTGCAAGCT 3'
5' AGCTTGCACT3'
what are the 3 types of lipids found in cells and what is the difference between them?
steroids- four-ring structure
fats (triglycerides)- three fatty acids linked to glycerol
phospholipids- glycerol, a phosphate group and two fatty acids
This specific transport protein uses ATP to move 3 sodium ions out of the cell and 2 potassium ions into the cell against their concentration gradients
sodium-potassium pump