A compound contains hydroxyl groups as its predominant functional group. What is true of this compound?
It should dissolve in water
A chemist wishes to make an organic molecule less acidic. What functional group should be added to the molecule?
From its atomic number of 15, it is possible to predict that the phosphorus atom has?
15 protons and 15 electrons
What polymer is not found in cells?
Which polymer contains sulfur?
What explains the attraction of water molecules to one another?
what bond is not considered to be a weak molecular attraction?
hydrophobic substances such as vegetable oil are?
nonpolar substances that repel water molecules
are mirror images of one another
buffers are substances that help resist shifts in pH by?
accepting H+ in acidic solutions
which macromolecular structure plays an essential role in hydrogen bonds?
alpha helix, protein tertiary structure, cellulose
polymerization of which macromolecular structures does not involve dehydration synthesis?
what polymers contain nitrogen?
protein and RNA
in what class of polymers is the backbone structure often branched?
the attraction of phospholipid molecules to form a bilayer involves?
exclusion of water from the bilayer structure
what two terms have the same meaning?
monosaccharide and sugar
which structures are characteristic of eukaryotic, but not prokaryotic cells?
which structures are characteristic of animal cells but not plant cells?
which structures are characteristic of plant cells but not animal cells?
which cell structure is made entirely of protein and RNA?
which eukaryotic cell structure is characterized by two biological membranes?
nucleus and mitochondria
where is DNA found in eukaryotic cells?
nucleus, mitochondria, and chloroplasts
which compartment often takes up much of the volume of a plant cell?
what eukaryotic cell structure is the site of most membrane synthesis?
what cellular activities do not involve microtubules?
what prevents membrane proteins from floating away from the membrane?
chloride ion channels are membrane structure that either are or include what in their structure?
the movement of potassium into an animal cell requires?
an energy source such as ATP or a proton gradient
if a cell is placed in pure water, why does it take up water?
water is able to leak across plasma membrane. the higher solute concentration of dissolved molecules inside a cell causes water to move into the cell by osmosis
the mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as?
if you know the change in free energy of a reaction. what does this value tell you?
whether is proceeds from left to right
what is the activation energy of a reaction?
the energy to which reaction intermediates must be brought before a reaction can proceed
why do two of the first three steps of glycolysis require ATP?
in both reactions a phosphate is added to glucose. addition of two phosphate groups make glucose unstable so it splits in two parts
for each glucose molecule metabolized in glycolysis , how many acetyl Co-A molecules are produced?
which process in eukaryotic cells will proceed normally with or without oxygen?
what is the immediate energy source that through coupling permits the synthesis to happen in cells?
hydrogen ion gradient across the inner mitochondrial membrane
hemoglobin is a blood protein that is made of four polypeptide chains. What is the term used to describe the protein structure created when multiple polypeptide subunits bind together
Macromolecules are polymers. If the monomers are nucleotides, what class of macromolecules are we talking about?
A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from:
a plant or an animal
where are ribosomes found in eukaryotic cells?
cytosol, rough endoplasmic reticulum, mitochondria, and chloroplasts
which of the following contains its own DNA and ribosomes?
where in a eukaryotic cell are proteins destined for lysosomes synthesized?
rough endoplasmic reticulum
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
smooth endoplasmic reticulum
What cytoskeletal elements are found in cilia and flagella in eukaryotic cells?
What distinguishes facilitated transport across a cell membrane from active transport?
Active transport requires the expenditure of chemical free energy, facilitated transport does not.
what transport process does osmosis depend on?
which membrane activity requires energy from ATP hydrolysis?
Na+ ions moving out of the cell
A series of enzymes catalyze the reaction X-->Y--> Z--> A. In the metabolic chain, product A binds to the active site of the enzyme that converts X to Y. This binding decreases the activity of the enzyme. Substance A functions as
a competitive inhibitor
Imagine a chemical reaction A --> B with a ΔG = -2kcal/mole. What can be done to change the reaction so that B --> A will actually happen?
add more reagent B
In a coupled reaction the positive ΔG of one partial reaction is overcome by the negative ΔG of another partial reaction. When the second half-reaction is ATP --> ADP + Pi, there is normally a reaction intermediate. What is the nature of this intermediate?
a phosphate group covalently bound to another organic molecule
in cellular biochemistry, what does an allosteric activator do?
binds to a regulatory site causing an allosteric enzyme to change its shape from inactive to active form
most of the NADH production in mitochondria comes from what group of reactions?
citric acid cycle
which aspect of respiration produces most of the cell's ATP?
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?
One of the end products of oxidative phorylation is ATP. The process is rather complicated. Where does the energy come from that is used to combine phosphate with ADP in mitochondria?
the combination of electrons from glucose with oxygen
where in the cell is molecular oxygen used in respiration?
oxygen accepts electrons from the electron transport chain