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