ESCI 30 Midterm 1
The equation, C6H12O6 + 6O2 →6CO2 + 6H2O (ATP + heat), describes what process?
Cell respiration
Osmosis describes the movement of water from an area of high to low solute concentration.
False
The Calvin cycle is only capable of fixing carbon dioxide in the dark.
False
The amount of available energy that can be used to do work is called
Free energy
Which DNA strand is complementary to 5′-ATTCGGTGA-3′?
3′-TAAGCCACT-5′
Atmospheric pollution of Sulfur and nitrogen compounds from power plants leads to:
Acid rain that acidifies lakes and streams
Why do cells communicate? Check all that apply A.) To signal changes in the environment B.) To coordinate activities C.) To signal apoptosis D.) To signal presence of substrate E.) To signal absence of substrate
All of the above
What process best characterizes Ca2+ movement from the cytosol (low Ca2+ concentration) into the endoplasmic reticulum (high Ca2+ concentration)?
Calcium movement involves active transport
Identify the reactant that produces oxygen in the light reaction of photosynthesis
H2O
Isotopes are different forms of the same element that:
differ in their number of neutrons
What would happen to a plant that is treated with a chemical that prevents electrons from moving through the electron transport chain?
It could not generate an electrochemical H+ gradient across a membrane
Fats and fatty acids
Linear structure of a fatty acid causes solid formation at room temperature
Suppose you wanted to investigate ideas on how polymerization of prebiotic organic molecules may have occurred on the early Earth. Which of the following scenarios might best be utilized for this?
Mix some RNA nucleotides in water and repeatedly wet and dry them on clay
Which is NOT a trait of the DNA double helix?
The double helix configuration is as twisted and condensed as DNA can become
In the reaction, 6CO2 + 6H2O →C6H12O6 + 6O2, which side should energy be placed on?
The left side as this is an endergonic reaction
Which of the following statements about the electron transport chain in cell respiration is correct.?
The loss in free energy of the electron initially donated by NADH is used to transport
What would you predict about a reaction that has a ΔG < 0?
The reaction will yield energy and is spontaneous.
The ultimate source of energy for reactions in a plant is ...
The sun
Which membrane component is most important for allowing large, charged molecules to pass through the membrane?
Transmembrane proteins
Bacteria commonly use N-acyl homoserine lactone as a signal molecule to coordinate biofilm formation.
True
Fluorescence microscopy enables researchers to label and visualize a particular type of cellular protein or organelle.
True
Sulfur 35 (35S) is an isotope of 32S. These elements differ in their number of neutrons.
True
The presence of integral proteins allows membranes to be selectively permeable to certain molecules.
True
Whether a signaling molecule operates locally or over long distances, it must bind to a specific receptor to elicit a cellular response.
True
A comparison of mitochondria and chloroplast shows that ...
both generate ATP via a H+ electrochemical gradient.
The organelles most likely to have to ability to divide and reproduce themselves like a cell would be:
both mitochondria and chloroplasts
Which portion of the photosynthetic apparatus absorbs light?
both photosystem I and photosystem II
Protobionts are thought to be the first nonliving structures that evolved into living cells. A critical characteristic of a protobiont that is found in both modern day prokaryotes and eukaryotes is
boundary membrane that separates external from internal environments
When one atom loses an electron to another atom, it results in the formation of:
cations and anions that form ionic bonds
In which organelle of the plant does photosynthesis takes place?
chloroplast
A key is placed into a keyhole, then turned, and the door opens. When considering the components of cell signaling, the action of turning the key would best correspond to ...
conformational change in the receptor once bound to the hormone
When epidermal growth factor binds to a(n) ________ receptor, the receptor phosphorylates itself, triggering a signal transduction pathway.
enzyme-linked
A significant role played by pH buffers is to
limit major shifts in the amount of H+ and OH- in solution
The major class of macromolecules that stores energy and makes up the major component of plasma membranes are
lipids
Blue light has ________ energy than red light and is ________ by a green leaf.
more, absorbed
Carbon and hydrogen have similar electronegativities and combine together to form hydrocarbon molecules. What type of bonds form between these atoms?
nonpolar covalent
NADPH is produced by
the light reactions alone
The atomic number of an atom is:
the number of protons in the atom
As the radius of a cell increases:
the surface to volume ratio decreases
What statement about the major and minor grooves is TRUE? A.) The major and minor grooves are not present in bacterial cells, because they have circular chromosomes B.) The major and minor grooves are important for DNA binding proteins to attach to the DNA C.) The major groove is formed from pyrimidines and the minor groove is formed from purines D.) The major groove runs in the 5' to 3' direction and the minor groove runs in the 3' to 5' direction E.) None of these statements are TRUE
B.) The major and minor grooves are important for DNA binding proteins to attach to the DNA
A chemical reaction that has a positive ΔG is correctly described as:
Endergonic
Enzymes are consumed in chemical reactions and must therefore be replenished
False
All of the following are a form of potential energy that can be used by a cell except: A) ATP. B) nitrogen. C) an electrical/ion gradient. D) concentration gradient. E) NADH.
Nitrogen
The four most common elements in the human body are:
Oxygen, Nitrogen, Hydrogen, Carbon
What are the two major components of cell membranes?
Phospholipids and proteins
The best way to describe cellular membranes is:
fluid with lipid rafts
A new flower species has a unique photosynthetic pigment. The leaves of this plant appear to be blue-green. What wavelengths of visible light does this pigment reflect?
green and blue
Water ...
has cohesive properties
Passive diffusion ...
is a spontaneous process
How does an enzyme work to catalyze a reaction?
it lowers the activation energy of the reaction
The nucleotides within DNA are composed of a
phosphate group, deoxyribose sugar, nitrogenous base
In a single strand of DNA, nucleotides are connected by which type of bond?
phosphodiester
Succulent plants such as cacti or pineapple
produce 4-carbon malate in the first step of carbon fixation.
A plant performing photosynthesis will
produce oxygen and consume carbon dioxide.
Apoptosis in cells can be best described as ...
programmed cell death
A protein's ________ structure contains helixes and sheets that result from hydrogen bonding between carboxyl and amino groups of the polypeptide chain.
secondary
Diabetics can be given insulin that binds to receptors on cells throughout the body increasing glucose uptake. Insulin is an example of a ...
signal
You are given two nucleic acids; one RNA and the other DNA. What are the main features to determine which is the DNA?
thymine instead of uracil and is a double-stranded structure