UNIT 1 Flashcards
What are the 5 points of cell theory?
- all organisms are made of cells
- the cell is the fundamental unit of life
- cells come from preexisting cells
- there is no life without cells
- the cell is the smallest unit of life
What are the three domains on the tree of life?
eukaria, bacteria, archaea
Why can the results from studies of cellular processes in the bacterium E. coli be applied to cellular processes that occur in humans?
It shares a common ancestor with eukaryotes so many processes are conserved.
Which cellular structures or compartments are found in all cells?
ribosomes, cytosol, plasma membrane
What differentiates eukaryotes from prokaryotes?
- prokaryotes do not have membrane bound compartments
- eukaryotes have a nucleus surrounded by a nuclear envelope, many membrane bound compartments such as mitochondria and chloroplasts
A human immunodeficiency virus (HIV) consists of a shell of proteins surrounding a single strand of RNA, all surrounded by a lipid bilayer.
List the macromolecules found in the virus.
RNA, proteins, lipids
Describe at least two reasons that a virus does not meet the criteria to be considered a cell.
- it cannot replicate on its own without a host cell
- no metabolism
How does a cell use carbon?
amino acids, lipids, carbohydrates, nucleic acid building blocks
How does a cell use nitrogen?
forming side chains of amino acids, forming nitrogenous bases,
How does a cell use oxygen?
building blocks for all macromolecules
How does a cell use phosphorous?
phosphate group attached to lipids, nucleotide building block
Which phase(s) is the overall pop. not actively dividing?
Lag phase
Which phase(s) is the overall pop. number not increasing?
lag phase, stationary phase, death phase
Which phase(s) is the overall pop. dividing exponentially?
exponential phase
Which phase(s) is the death rate higher than the growth rate?
death phase
Which phase(s) are the essential nutrients becoming limited?
stationary phase, and death phase
Which phase(s) is DNA being replicated prior to cell division?
lag, exponential, stationary, death
In which phase(s) is transcription and translation occurring within the cell?
lag, exponential, stationary, death
which phase is binary fission occurring in cells?
exponential, stationary, death
What would happen if lactose was removed from the media mid-way through A?
the cells would not enter the exponential phase and would stay in lag phase
What would happen if lactose was removed from the media mid-way through B?
the cells would enter stationary phase sooner and the maximum number of cells would be lower
What would happen if lactose was removed from the media mid-way through C?
the cells may enter the death phase sooner, and the death rate of cells would remain the same
What would happen if lactose was removed from the media mid-way through D?
nothing
An example of a noncovalent bond or interaction that is common within and between macromolecules is a
hydrogen bond
Two large proteins are interacting and held together by non-covalent bonds (interactions) on their surfaces. Why can these non-covalent bonds hold the proteins together?
There are many bonds
In macromolecular synthesis/polymerization, what type of bond would join two amino acid subunits?
peptide bond
In macromolecular synthesis/polymerization, what type of bond would join two monosaccharide subunits?
glycosidic
In macromolecular synthesis/polymerization, what type of bond would join two nucleotide subunits?
phosphodiester bond
In lipid synthesis/polymerization, what type of bond would join two fatty acid tails to a glycerol backbone?
ester bond
A hydrogen bond is a special case of which non-covalent interaction?
PD-PD
When two atoms are involved in a polar covalent bond, what is the charge on each atom?
One has a permanent partial positive (delta+) and the other a permanent partial negative (delta-).
When two atoms are involved in a nonpolar covalent bond, what is the charge on each atom?
Both atoms fluctuate between partial positive and partial negative charges.
When an atom is part of a polar covalent bond, what types of noncovalent interactions are possible for this atom to be part of, with another atom?
ion-PD, PD-PD, PD-ID
When an atom is part of a nonpolar covalent bond, what is the strongest noncovalent interaction that it is possible for this atom to be part of, with another atom?
PD-ID
When an atom or functional group is ionized (e.g. an NH3+ group or a COO- group) what is the strongest type of noncovalent interaction(s) is possible for it to be part of, with another atom/group?
ionic
A membrane protein made up of a single polypeptide forms an alpha helix as it crosses the lipid bilayer. What can you say about this protein?
- The R-groups found within the transmembrane domain are non-polar.
- The R-group interactions are the primary factor stabilizing its secondary structure.
- Hydrogen bonds among backbone carbonyl and amide groups can be found in the transmembrane domain.
- The quaternary structure is determined by its interactions with fatty acid tails.
- Hydrogen bonds among backbone carbonyl and amide groups can be found in the transmembrane domain.
- the R-groups found within the transmembrane domain are non-polar
A RNA-binding protein binds to the nucleic acid backbone using the amino acyl residue histidine. What do you predict would happen to RNA binding activity if histidine was replaced with isoleucine?
Decreased binding of the protein to RNA
What is the correct order that a monomer of RNA are connected?
phosphate-sugar-base
Which region is required for a membrane carrier to move a solute against its concentration gradient, but is not required for a channel?
Active site for ATP binding
What is true for BOTH the lag and stationary phase?
- Cells synthesize macromolecules for those conditions.
- Most cells are dividing.
- Cells are active in binary fission with a similar number undergoing cell death.
- The cells are encountering new growth conditions.
- Cells synthesize macromolecules for those conditions
- cells are encountering new growth conditions
Which of the following statements are TRUE for the formation of lipid micelles in water? [Choose all that apply]
- The phospholipids that form micelles can have one, two, or three fatty acid tails.
- The entropy of the phospholipids increases during micelle formation.
- The entropy of the water molecules increases when non polar lipid tails group together.
- Lipids form micelles because the phospholipids cannot interact with water.
- The assembly is spontaneous with negative delta G.
True:
- the entropy of the water molecules increases when non-polar lipid tails group together
- the assembly is spontaneous with negative delta G
