Topic 1.1 - 2.2 Review of WS questions Flashcards
Carbon, hydrogen, nitrogen, and sulfur are elements found in living cells. Which is the least common?
sulphur
Which of the following substances are organic?
I. Lipids
II. Water
III. Carbon dioxide
Lipids
What causes water to have a relatively high boiling point?
Hydrogen bonds between water molecules
What role does iron play in living organisms?
As a component of proteins
Explain how the properties of water, that are essential to living things, arise from the dipolar nature of water.
- oxygen in water is slightly negatively charged and hydrogens are slightly positive
- hydrogen bonding due to dipolar nature
- Water molecules are cohesive due to hydrogen bonding
- cohesion useful in xylem transport
- hydrogen bonds with other structures giving adhesive properties
Which of the following features are correct for hydrogen bonding?
I. It is involved in the cohesion of water.
II. It results in the thermal properties of water.
III. It is a bond within the water molecule.
I. It is involved in the cohesion of water.
II. It results in the thermal properties of water.
What is a role of carbohydrates in animal cells?
As energy storage
define organic
organic compounds contain carbon atoms
state the three most common occurring elements
Carbon, Hydrogen, Oxygen
State one function for each of the main four elements in organisms. (Carbon, Hydrogen, Oxygen, Nitrogen - CHON)
Carbon: forms the foundation of all four classes of organic compounds
Hydrogen: reducing agent in photosynthesis and cellular respiration
Oxygen: used in aerobic respiration in cells to make ATP
Nitrogen: formation of amino acids
What properties of water are due to hydrogen bonding?
High specific heat capacity
High boiling point
ice floats on liquid water
High heat of vaporization
What is the decreasing abundance order of elements found in living organisms?
CHON
Carbon, Hydrogen, Oxygen, Nitrogen
SPONCHNa CaFe
Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen, Sodium, Calcium, Iron
Sulfur in living organisms
Amino acids (proteins - disulfide bridges)
Phosphorus in living organisms
Phospholipids, Nucleic acids (DNA and RNA), ATP
Oxygen in living organisms
Amino acids (proteins), carbohydrates, lipids, nucleic acids (dna and rna) aerobic respiration
Nitrogen in living organisms
amino acids (proteins - amine groups), Nucleic acids (Dna and Rna nitrogenous bases) ATP
Carbon in living organisms
forms the foundation for all organic molecules/compounds, carbohydrates, lipids, proteins, nucleic acids
Hydrogen in living organisms
amino acids (proteins) carbohydrates, lipids, nucleic acids, respiration, photosynthesis
Sodium in living organisms
osmoregulation, action potentials (nerve signals - sodium channels open, sodium ions rush into nerve cell causing depolarization)
Calcium in living organisms
muscle contraction, nerve cell transmission (Ca ions rush into nerve cell causing vesicles with neurotransmitter to bind with presynaptic membrane and “dump” neurotransmitter into synaptic cleft)
Iron in living organisms
in cytochromes (proteins that make up the electron transport chain - respiration and photosynthesis) in hemoglobin (oxygen transport in blood)
Muscle contraction
calcium is released from sarcoplasmic reticulum to bind to troponin to expose myosin binding sites
Outline one therapeutic use of stem cells
Stem cells can be used to replace damaged or diseased tissue with healthy and functioning cells. You trigger the cell with a solution to trigger their differentiation into the desired cell type and then surgically implant the cells into the tissue. Then you suppress the immune system to prevent rejection and monitor the cell growth watching for cancerous activity. An example of this is the treatment of Stargardt’s Disease or bone marrow transplant
bone marrow - stem cells give rise to WBC’s, RBC’s, and platelets. used to treat cancer patients, chemotherapy = kills both cancer and healthy cells (can’t produce blood cells on their own) bone marrow cells harvested BEFORE chemo (or use a donor); after chemo cells are translated back into the body to produce healthy blood cells again
Distinguish between resolution and magnification when applied to electron microscopy
magnification - the number in which the object is blown up (x40)
resolution allows the viewer to see detail and distinguish between different specimen or cells
What is the correct order of increasing size for the width of a virus, the width of bacterium, the thickness of a cell surface membrane, and the diameter of a eukaryotic cell?
1) the thickness of a cell surface membrane
2) the width of a virus
3) the width of a bacterium
4) the diameter of a eukaryotic cell
compare the relative size of a molecule, thickness of a cell membrane, viruses, bacteria, organelles, and eukaryotic cells
molecule = 1 nm thickness of a cell membrane = 10 nm viruses = 100 nm bacteria = 1 um organelles = up to 10 um eukaryotic cells = up to 100 um
1, 10, 100 (first three are nm, last three are um)
Explain the importance of the surface area to volume ratio in limiting cell size
cell has larger surface area - able to move more wastes and heat out of the cell and resources into the cell
as cell continues to grow - volume will increase at a faster rate than the surface area
- decreases the SA/C ratio
*if the metabolic rate is greater than the exchange rate, the cell will eventually die
*if cell becomes to large - they will divide in order to restore the SA/V ratio
A student observes and draws an Amoeba, using the high power lens of a microscope. The diameter of the drawing is 100 mm. The actual diameter of the Amoeba is 100 um. What is the magnification of the drawing
100 mm / 100 um = 1000
If a red blood cell has a diameter of 8 um and a student shows it with a diameter of 40 mm in a drawing, what is the magnification of the drawing?
40 mm / 8 um = x5000
What method provides biochemical evidence that cells have begun to differentiate?
Analysis of the proteins
What functions of life are carried out by all unicellular organisms?
growth, homeostasis, metabolism, response
What happens to the cell surface area to volume ratio as a cell grows?
It decreases, so rate of gas exchange is low
cells divide when they are too large to maintain high SA:V ratio
In viewing an electron micrograph of a cell, ribosomes, pili, and a single circular chromosome are observed. What other structure is likely to be present?
a plasmid
What describes the functions of the following organelles?
processing of proteins
synthesis of proteins for cell secretion
Which of the following structures are present in both plant and animal cells?
cell wall
chloroplast
mitochondria
Mitochondria
State one function of the mitochondria
(powerhouse of the cell)
Produces ATP
In what way are eukaryotic chromosomes different from prokaryotic chromosomes?
a) protein is present; protein is absent
b) DNA is present; DNA is absent
c) RNA is present; RNA is absent
d) RNA is absent; RNA is present
a) protein is present; protein is absent
What organelles have a transport function?
Golgi apparatus and endoplasmic reticulum
What pair of features is correct for both plant and prokaryotic cells?
a) able to change shape; fixed shape
b) contains DNA associated w protein; contains naked DNA
c) DNA enclosed by a membrane; DNA associated with protein
d) chloroplasts may be present
b) contains DNA associated w protein; contains naked DNA
prokaryotic and eukaryotic cells both have…
ribosomes
which of the following features is/are present in mitochondria but not in chloroplasts?
DNA and ribosomes
outer and inner membranes
cristae
cristae
which combination of features is found in most plant and animals cells?
a) plasma membrane, lyosome, golgi apparatus
b) cytoplasm, mitochondria, ribosomes
c) rough ER, nucleus, centrioles
d) plastids, cytoplasm, nucleus
b) cytoplasm, mitochondria, ribosomes
what route is used to export proteins from the cell?
rough endoplasmic reticulum -> golgi apparatus -> plasma membrane
state one difference between the proteins produced by free ribosomes and those produced by ribosomes attached to the endoplasmic reticulum
the protein from the RER is sent to the Golgi apparatus while the protein from the free ribosomes make proteins that stay in the cell
how many mm equal um
1 mm = 1000 um
state one function of the lysosome
hydrolytic enzymes for intercellular digestion (digestion of structures that are not needed within cells)
state one function of the golgi apparatus
transports cellular materials
state one function of the rough endoplasmic reticulum (RER)
protein synthesis
state one function of the nucleus
cell control and reproduction
storage and protection of chromosomes
state one function of the mitochondria
produces ATP
state the function of the ribosome
protein synthesis or making proteins that stay in the cell
structure of the nucleus
region containing chromosomes, surrounded by a double membrane in which there are pores
structure of ribosome
small spherical structures consisting of two subunits
structure of lysosome
spherical organelles, surrounded by a single membrane and containing hydrolytic enzymes
structure of mitochondria
organelles surrounded by two membranes, the inner of which is folded inwards
What is a characteristic of organelles
they are sub-cellular
What are the three domains of living organisms
archaea, eubacteria, eukaryotes
what is the difference between a cell in the G1 phase and a cell in the G2 phase of the cell cycle
a cell in the g2 phase would have more mitochondria than a cell in the g1 phase
what are homologous chromosomes
non-identical chromosomes with the same genes in the same sequence but not necessarily the same alleles
A somatic cell in a male chimpanzee contains 48 chromosomes. It is about to undergo mitosis. How many molecules of DNA will be present in the nucleus of the cells just after mitosis?
48
During the reproduction in flowering plants, an embryo sac is produced, containing one haploid nucleus. This haploid divides by mitosis three times. What is produced?
8 haploid cells
which of the following does not occur during interphase
replication
translation
cytokinesis
an increase in the number of mitochondria
cytokinesis
Deduce two processes that occur in human cells during interphase of the cell cycle, but not during mitosis
DNA synthesis
cell growth
What is the sequence of stages during the cell cycle?
G1 - S - G2 - mitosis - cytokinesis
state the process that results in tumor (cancer) formation or development
uncontrolled cell division
which events occur during the g1 phase and the s phase of the cell cycle?
G1 phase - cell grows
S phase - DNA replicates
How can cells in a multicellular organism differentiate?
They express some of their genes but not others
What happens during the G2 stage of interphase?
Synthesis of proteins
Which of the following take place during either interphase or mitosis in animal cells?
reformation of nuclear membranes
pairing of homologous chromosomes
DNA replication
Re-formation of nuclear membranes and DNA replication
