BIO102
At what temperature is diffusion (=Brownian motion) fully stopped?
0 degrees Kelvin
When working in the laboratory with chemicals, what personal protective equipment (PPE) should be worn at all times?
Always wear goggles and lab coats. Gloves should also be worn when needed
What is a hypotonic solution?
An external solution with a lower concentration of solute than inside a cell
If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells?
Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.
Erwin Chargaff discovered there are not equal amounts of all four nitrogenous bases in an organism. However, the amount of adenine always equals the amount of thymine, and likewise, the amount of guanine equals cytosine in any organism. This became known as part of __________.
Chargaff's rules
Which of the statements regarding enzymes is false?
Enzymes provide activation energy for reactions
A trans fat is:
a form of unsaturated fat with the hydrogen atoms neighboring the double bond across from each other rather than on the same side of the double bond
Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein?
a large polar molecule
The relationship between an enzyme and a reactant molecule can best be described as:
a temporary association
Glucose is a six-carbon sugar that diffuses slowly through membranes. The cells lining the small intestine, however, rapidly move glucose from the gut into their cytoplasm. This occurs whether the gut concentrations of glucose are higher or lower than the glucose concentrations in intestinal cell cytoplasm. Using this information, which transport mechanism is most likely responsible for the glucose transport in intestinal cells?
active transport
Metabolism is best defined as which of the following?
all of the stated
A selectively permeable membrane:
allows certain size substances to enter and leave
Which of the following is a functional group that is part of a building block of proteins?
amino
What are the monomers of globulins?
amino acids
A hypothesis should be falsifiable means
an experiment can be set up to disprove it
When an atom donates an electron to another atom, it becomes
an ion
Caffeine binds to adenosine receptors and in this way inhibits the action of this receptor. Here caffeine is known as a (an)........
antagonist
You are heating a substance in a test tube. Always point the open end of the tube:
away from all people
Hydrolysis could be correctly described as the
breaking of a long-chain compound into its subunits by adding water molecules to its structure between the subunits
Which of these only has unbranched chains?
cellulose
Which molecule absorbs the energy of a photon in photosynthesis?
chlorophyll
A...........................is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity
cofactor
Nitrogenous bases, such as adenine and thymine, that pair together by forming hydrogen bonds between two strands of DNA are said to be _____
complementary
The difference in the concentration of a substance across a space is called:
concentration gradient
All the things in an experiment that must be the same to make it fair are called
controlled variables or constants
A cell has a membrane potential of -100 mV (more negative inside than outside) and has 1,000 times more calcium ions outside the cell than inside. Which of the following best describes a mechanism by which Ca2+ enters the cell?
cotransport of Ca2+ into the cell with Cl- ions
The two pyrimidines in DNA are _____. The two purines are _____.
cytosine & thymine, guanine & adenine
Active transport must function continuously because __________.
diffusion is constantly moving the solutes in the other direction
In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________.
double helix
For every 10 degree C increase in temperature, the rate of chemical reactions ____
doubles
Molecular movement continues even when there is no overall change in concentration. This is referred to as:
dynamic equilibrium
From where does a heterotroph directly obtain its energy?
eating other organisms
What is the energy of a photon first used to do in photosynthesis?
energize an electron
The first law of thermodynamics states
energy can neither be created nor destroyed
Which of the following transport systems require energy?
exocytosis
Nucleotides contain ___________ sugars.
five carbon
Water moves via osmosis _________.
from an area with a low concentration of solutes to an area with a higher one
An example of a monosaccharide is _______
galactose
What organic compound do brain cells primarily rely on for fuel?
glucose
What two products result from photosynthesis?
glucose and oxygen
A fat molecule, such as a triglyceride, consists of two main components—............and ................
glycerol and fatty acids
A phospholipid ________.
has both polar and nonpolar regions
C6 H12 O6 is the chemical formula for a ________.
hexose monosaccharide
Which type of bond represents a weak chemical bond?
hydrogen
A cell is placed into a solution and the cell shrinks. Which of the following is true regarding the solution?
hypertonic solution
______________ bonds involve the transfer of electrons from one atom to another creating opposite charges which attract each other.
ionic
Uracil............
is a pyrimidine
Which is not a true polymer?
lipids
The transition state of a catalyzed reaction is
lower in energy than that of an uncatalyzed reaction
A pentose sugar is a part of the monomer used to build which type of macromolecule?
nucleic acids
DNA and RNA are examples of which family of biological molecules?
nucleic acids
In eukaryotes, DNA wraps around histones and assembles into units called......, which are then tightly packed together as chromatin.
nucleosomes
Because the human body is 60% water, an important process which helps humans and all living things maintain a "normal" internal cellular environment even when external surroundings are constantly changing is:
osmosis
An endergonic reaction:
overall requires energy
When substances move in and out of cells using only their own kinetic energy this is called:
passive transport
Which of the following is not a type of work performed by living cells?
phototrophism
A dehydration reaction typically produces:
polymers
Cellulose and starch are examples of ________.
polysaccharides
Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
protein
Which of the following macromolecules would likely contain sulfur?
proteins
The characteristic that gives an element its distinctive properties is its number of
protons
The three main stages of cell signaling are:
reception, transduction, response
Which of the following is found both in eukaryotic and prokaryotic cells?
ribosomes
cAMP is an important molecule that is part of several signaling cascades. It is classified as a __________ messenger and it can __________ the signal.
second . . . amplify
Direct cellular connections such as gap junctions in animal cells and plasmodesmata in plant cells permit:
second messengers produced in one cell to rapidly diffuse into and stimulate events in surrounding cells.
Genes are _____.
sequences of DNA nucleotides
Which of the following is not a property of ionic bonds?
sharing of electrons
A hydrolase
splits a bond by adding a water molecule
Plants produce oxygen when they photosynthesize. Where does the oxygen come from?
splitting water molecules
ORGANIC COMPOUNDS that are composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio are called:
sugars
A scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. In this experiment the independent variable is:
the amount of salt in the water
Watson and Crick are famous for discovering _____.
the structure of DNA
You are heating a piece of glass and now want to pick it up. You should
use tongs
Inductive reasoning is a form of logical thinking that:
uses related observations to arrive at a general conclusion
When placed in a hypotonic solution, plant cells:
will increase in turgor pressure
What are the monomers of glycogen?
Monosacharides
Is it permissible to have any drink or food in the laboratory?
Never
Can open-toed or open-heeled shoes be worn in the lab?
No
What is the major difference between diffusion and osmosis?
Osmosis transports water while diffusion transports solute
Nitric oxide is which of these types of signals?
Paracrine signal
When diluting an acid with water, always remember to:
Pour acid into water
Where in the laboratory should waste chemicals be disposed of properly?
Satellite Accumulation Area (SAA) for proper disposal of chemical waste
What is the name of the DNA replication process that produces two identical DNA molecules, each consisting of one parent strand and one daughter strand?
Semiconservative DNA replication
Which of the following statements about double-stranded DNA is false?
The bases are on the outside of the helix
Lab personnel should label all containers containing chemicals or compounds made in the lab with:
The chemicals' full names
Consider the transport of protons and sucrose into a plant cell by the sucrose-proton cotransport protein. Plant cells continuously produce a proton gradient by using the energy of ATP hydrolysis to pump protons out of the cell. Why, in the absence of sucrose, don't protons move back into the cell through the sucrose-proton cotransport protein?
The movement of protons through the cotransport protein cannot occur unless sucrose also moves at the same time.
Which of the following statements about hydrogen bonds is FALSE?
They mostly occur between carbon atoms.
Which statement about thylakoids in eukaryotes is not correct?
Thylakoids exist as a maze of folded membranes.
Which of the following molecules can be found inside of a cell? I. Cyclic adenosine monophosphate (cAMP) II. Protein kinase A III. Protein kinase C
I, II, and III
Listed below are events that occur during a signal transduction pathway. I. The plasma membrane receptor interacts with an effector protein II. Second messenger molecules are released III. Ligand binds to the plasma membrane receptor Which of the following lists these events in the correct order?
III, I, II
In the event a chemical spill (such as an acid or base gets into your eyes or on your skin), what should you do?
Immediately rinse affected area in running water for 15 minutes and get a cold shower if needed
Which of the following is true regarding a transmembrane receptor?
It has both hydrophobic and hydrophilic regions and the ligand binds on the hydrophilic regions
A type III secretion system is a mechanism several bacteria use to evade the immune system. They insert a syringe-like structure into a nearby host cell and secrete effector proteins that kill the host cell. What term best describes this kind of signaling?
Juxtacrine
Nitrogen has an atomic number of seven. How many electron shells does it likely have?
2
A piece of double stranded DNA has 30% A, what will be the % of G?
20%
Which of the following bases pairs with guanine?
Cytosine
In an experiment, the ____ variable is the outcome or effect being measured and the ____ variable is the potential cause of that effect that is manipulated by the experimenter.
Dependent; Independent
What is the major difference between diffusion and facilitated diffusion?
FD requires a specific carrier
Name the largest family of cell surface receptors
GPCR
Name the simplest amino acid
Glycine
