Questions and Definitions Flashcards
What components are required to make cells?
- Cell membrane
- DNA and RNA protein
- Metabolism
What’s an organism?
an individual creature Ex: animals, plant, or single-celled life form.
Can eukaryotes be unicellular multicellular or both?
It can be both
Nuclei is..
plural of nucleus
Protists are?
unicellular eukaryotes
What are the defining features of a cell?
Which of the following statements is correct with respect to Cell Theory?
A. Daughter cells always come from mother cells.
B. Organisms must contain more than one cell.
C. Some living organisms, like viruses, can exist
without cells.
D. In extreme environments, cells can arise
spontaneously.
Bacterial cells
A
Select all of the characteristics that define cells as the smallest unit of life (choose all that apply)
A. They are capable of metabolism.
B. They don’t rely on any other cells for nutrition.
C. They have the capacity to replicate themselves.
D. They are surrounded by a cell membrane.
E. They have DNA to make RNA to make proteins. Bacterial cells
A, C, D, E
Q. What is the water content range of a typical
human body?
A. 1-3%
B. 5-8%
C. 20-30%
D. 50-60%
E. 90-95%
D
NOTE: About 66% of
this water is inside
cells
The polarity of the nucleic acid polymer is due
to:
A. The way that the glycosidic bonds form
between the sugar groups.
B. The different chemical nature of the 5’
phosphate group and the 3’ hydroxyl ends.
C. The charged molecules on the 5’ carbon.
D. The uneven electron distribution between
carbon and oxygen.
E. The bases that pair A-T and C-G.OH
B
Polymers of nucleic acids, proteins
and carbohydrates have functional
groups that make them hydrophilic.
This is because:
A. They love water.
B. The polymer has two chemically distinct ends.
C. The covalent bonds that link the monomers are distinct in each type
of polymer.
D. The polymers have polar, electronegative molecular groups.
E. These molecules come from the north and south poles.
D
Why are there no water
molecules (red) inside the
bilayer?
Why are there no water
molecules (red) inside the
bilayer?
A. Water cannot interact with the
head group
B. Water cannot interact with the
fatty acid tail
C. There is more disorder if the
water does not interact with the
lipid tails
D. The head groups shield water
from entering
E. There is more order if the fatty
acid tails interact with each
other
C
What is one difference and one
similarity between a liposome and a
cell membrane?
A. Similarity- both have bilayers; Difference- cell membrane has proteins.
B. Similarity- both have phospholipids; Difference- cell membrane has cholesterol.
C. Similarity- both are impermeable; Difference- liposome is more impermeable.
D. Similarity- both have phospholipids; Difference- cell membrane lacks proteins.
A
What kinds of non-covalent interactions can
form between this phosphotidyl serine and
water? Choose all that apply
A. Permanent dipole-ionic
B. Permanent dipole-permanent dipole
C. H-bond
D. Induced dipole-permanent dipole
E. Induced dipole-induced dipole
A,B,C,D
What non-covalent interaction describes
how the fatty acyl tail interacts with
another fatty acyl tail?
A. Induced dipole-induced dipole
B. Induced dipole-permanent dipole
C. Permanent dipole-permanent dipole
D. Water will not interact with the fatty
acid tail
E. Hydrophobic effect
A
What drives the negative DG
during membrane assembly?
A. Entropy of water
B. Enthalpy of water
C. Enthalpy of nonpolar
lipids
D. Entropy of ordered lipids
CQQ
ΔG = ΔH + (-TΔS)
A
Phospholipids placed in a mixture of oil droplets (also
called lipid droplet, LD) and water form a monolayer
around the oil droplet. Why? Choose all that apply.
1. All of the space in the lipid droplet is already occupied
by the triacylglycerol.
2. The phospholipid heads interact with water.
3. Triacylglycerol is nonpolar, and the phospholipids tails
are also non-polar.
4. Triacylglycerol and phospholipids are both
amphipathic.
2,3
Why is it energetically favourable for molecules to move
from a region of higher concentration to one of lower
concentration?
A. There is more entropy/disorder once they are dispersed
so the DG is negative.
B. Their enthalpy is increased so the DG is positive.
C. The water molecules have more order so the DG is
negative.
D. They reach equilibrium where the energy is equal.
A
Peptide bonds are formed…
(choose all that apply)
A. On ribosomes during
translation.
B. During the reading of mRNA.
C. During transcription of a gene.
D. Between an amino and
carboxyl group of amino acids.
E. Among R-groups by
noncovalent interactions.
A, B, D
Which of the following are true about an alpha
helix spanning a lipid bilayer?
Choose all that apply
A. The secondary structure is stabilized by
H-bonds between R-groups.
B. The R-groups must be hydrophilic to
interact with fatty acids.
C. The peptide backbone in the helix is
shielded from the fatty acid tails by the
hydrophobic R-groups.
D. The secondary structure is stabilized by
H-bonds between amide and carbonyl
groups.
C, D
Thinking about what you learned about the thermodynamics of lipid bilayer
formation, why do you think that protein folding is a spontaneous process?
A.The enthalpy of water increases when R-groups form H-bonds
B.The enthalpy of induced dipole-induced dipole (VanderWaals
interactions) increase when nonpolar R groups cluster together.
C.The entropy of water increases when nonpolar groups cluster together,
away from water.
D.The entropy of water decreases when nonpolar groups cluster together
C
Why would changing a glycine to an aspartate lead to a
dysfunctional protein for patients with cystic fibrosis?
A. Changing a small nonpolar amino acid for a big
charged amino acid could disrupt ID-ID interactions.
B. Changing a H for a COO- could introduce new ionic
interactions with positively charged R-groups.
C. Changing glycine for another amino acid would
affect the covalent bonds of the polypeptide.
D. Aspartate would form ion-PD bonds with water, so
it could move its position from inside to outside the
protein.
Choose all that apply:
A, D
One species of ants has
just two chromosomes
making up its genome.
Following cell division,
how many DNA double
helices are found in
each cell?
A.1
B.2
C.4
D.8
9
B
Given your knowledge of chemistry for biology, what do
you predict about the sugars and phosphodiester bonds
that make the backbone of DNA?
A. They are hydrophilic.
B. They are hydrophobic.
C. The antiparallel strands will repel
each other.
D. They are non-polar.
A
