ANPS Lab 1

Calcium's atomic number is 20. It forms ions with 18 electrons. What is the electrical charge of a calcium ion?

+2

An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particle does it contain?

- 8 protons, 8 electrons, and 10 neutrons The atomic number is the number of protons in an atom, and the atom will have the same number of electrons, to balance the electrical charge. Mass number is the number of protons plus the number of neutrons, so subtracting atomic number from mass number reveals the number of neutrons.

Vinegar, which has a pH of 3, has a H+ concentration that is __________________ than coffee, which has a pH of 5.

100 times more concentrated

The first electron shell of an atom can hold two electrons, while the second shell can hold up to _____________ electrons.

8

Which set of membrane proteins in the figure depicts the transport of solute molecules across the membrane?

A both passive and active transport processes of solutes mediated by integral membrane proteins.

Which of the following events occurs during transcription?

A molecule of RNA is formed based on the sequence of nucleotides in DNA. - During transcription, RNA nucleotides line up with their complementary DNA partners, transcribing the information in DNA into RNA.

Which of the following best describes the difference between active and passive transport mechanisms?

Active mechanisms use energy to move solutes against their concentration gradients. Passive mechanism move solutes with their concentration gradients.

What is the difference between active and passive transport across the plasma membrane?

Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles moving down their concentration gradient.

In a covalent bond,

Atoms share one or more pairs of electrons.

Which of the following statements about cells is FALSE?

Cells join together to form organelles, which then form our organs and organ systems.

Put the following steps of protein synthesis in the correct order: 1. mRNA is produced in the nucleus 2. Ribosome moves along mRNA 3. DNA uncoils for transcription 4. Polypeptide is produced 5. tRNA brings amino acids to ribosome 6. mRNA travels to ribosome

DNA uncoils for transcription mRNA is produced in the nucleus mRNA travels to ribosome Ribosome moves along mRNA tRNA brings amino acids to ribosome Polypeptide is produced

Which of the following statements is true?

During exocytosis, substances from inside the cell are moved outside. - Vesicular transport processes that eject substances from the cell interior into the extracellular fluid are called exocytosis. Transport of substances by exocytosis is considered an active process - it requires energy in the form of ATP.

Phagocytosis and pinocytosis are both forms of exocytosis

False - endocytosis

Cells soaking in an isotonic solution will lose water and shrink.

False In an isotonic solution, the concentration of solutes is the same as the concentration of solutes in the cell. This means that there will be no net movement of water from the cell, or into the cell, so the cell will stay the same size.

Which of the following lists, in correct order, the phases of interphase?

G1, S, and G2

The organelle where cell proteins are modified and packaged is the

Golgi apparatus

What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?

In facilitated diffusion, molecules only move with the aid of a protein in the membrane.

Where would you find interstitial fluid?

In the extracellular compartment

How do ions form ionic bonds?

Ions of opposite electrical charges are attracted to each other to balance the charges.

Think about a 10% saline solution (saline refers to salt.). Which of the following is a correct statement?

It contains 10% solute and 90% solvent.

How is pH defined?

It is the measure of the concentration of hydrogen ions (H+) in a solution

Dehydration and fluid loss have several adverse effects on patient wellbeing. What type of IV fluids are commonly used in these circumstances?

Lactated Ringer's solution or Normal saline solution

Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?

No, because the atoms have only 6 valence electrons, but need 8 for stability.

Which of the following distinguishes hydrogen bonds from covalent bonds?

Only hydrogen bonds can form between molecules.

What explains the negative charge on the oxygen atom within the water molecule?

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen.

Which set of membrane proteins in the figure depicts an interaction between two separate cells?

Panel D shows recognition of one cell by another via the glycocalyx. Notice that there are two complete lipid bilayers, which suggests that there are two cell membranes, and therefore two cells.

The enzyme that synthesizes the RNA strand during transcription is:

RNA polymerase

What occurs during the elongation phase of transcription?

RNA polymerase chooses nucleotides that are complementary to the DNA template strand and adds them one at a time, building the mRNA transcript.

Having the correct concentration of which chemical is most important in rehydrating your patients?

Sodium (Na+)

Solution A is a 2% salt solution and solution B is a 12% salt solution. Which phrase correctly describes the relationship between solution A and solution B?

Solution A is hypotonic to solution B

By which mechanism would a steroid molecule diffuse into the cell?

Steroid molecules are nonpolar fat-soluble (lipid soluble) molecules, which would be expected to diffuse directly across the phospholipid bilayer. Such solutes do not require a membrane protein to facilitate transport.

During which of the following phases does DNA replication occur?

Synthesis or S phase

What can we infer if we see a large number of mitochondria in a cell?

The cell has a great metabolic demand.

If a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellular fluid. What do you predict will happen to the person's cells?

The cells will lose water and shrink. crenation

Which of the following is true of polar covalent bonds?

The electrons are shared unequally.

If a hydrogen atom has an atomic number of 1, and a mass number of 1, what does this tell us about the hydrogen atom?

The hydrogen atom has 1 proton and no neutrons. - The mass number of an atom describes the number of protons plus the number of neutrons in that atom. - We also know that every atom has the same number of electrons and protons, so hydrogen also has one electron (since it has one proton).

Before the mRNA transcribed from a gene can be used to create a protein, what must occur?

The introns, or non-coding regions, must be removed from the pre-mRNA molecule.

What must happen to the polypeptide chain before it becomes a functional protein?

The polypeptide chain must be folded into the final 3-dimensional shape.

Which of the following is true of electrolytes?

They are ionic compounds.

Which of the following occurs during a single cycle of the sodium-potassium exchange pump?

Three Na+ ions are transported out of the cell.

The molecule that brings the proper amino acid into place at the ribosome for the elongation of a new polypeptide is called

Transfer RNA (tRNA) molecules carry the amino acids to the ribosomes.

Which of the following is not a result of hydrogen bonds?

Two hydrogen atoms join together to form a molecule of hydrogen gas. - Hydrogen bonds occur when there are polar covalent molecules present, but hydrogen atoms join with each other through nonpolar covalent bonds.

The mRNA sequence that is complementary to the sequence ATC on the DNA template strand is

UAG UAG is the mRNA sequence that is complementary to the DNA sequence ATC. Remember, there is no T (thymine) base in RNA, so U is the mRNA base that is complementary to A (adenine) in DNA. G (guanosine) and C (cytosine) are complementary in either DNA or RNA molecules.

A sequence of three nucleotides on mRNA is called:

a codon - During translation, each mRNA codon is matched with an anti-codon on a tRNA molecule that carries a specific amino acid.

Which cellular organelle is seen in this figure? What is the function of a a mitochondrion

a mitochondrion to produce energy in the form of ATP

Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not?

Yes, because they can become more stable by doing so.

After the transfer of an electron, sodium will form an ion with __________.

a charge of +1

The mechanism depicted in B would most likely mediate the diffusion of which of the following solutes?

a sugar

major function of proteins in the cell membrane

acting as receptors anchoring cells to other structures acting as transport carriers forming channels

Movement of a solute against its concentration gradient by a carrier protein is called __________.

active transport

What is an ion?

an atom that has either gained or lost electron(s)

What holds the sodium and chloride ions together in a chemical bond?

an electrical attraction between opposite charges

What is the name for the 3 nucleotide sequence on a tRNA molecule?

anti-codon

During osmosis, water molecules can move across the plasma membrane through channels called

aquaporins

Nonpolar molecules

are the result of equal sharing of electrons between the atoms of the molecule.

Which of the following is not produced through chemical bonding?

atoms

The vast majority of the atoms in our body come from which 4 elements? These 4 elements comprise approximately 96% of our body weight.

carbon, oxygen, hydrogen, and nitrogen.

Carriers transport solutes across the plasma membrane by __________.

changing shape as the solutes bind, causing the solutes to move across the membrane

Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest?

covalent, ionic, hydrogen

During late anaphase, the division of the cytoplasm begins. A cleavage furrow forms over the center of the cell and continues to deepen until it pinches the cytoplasm into two parts, yielding 2 daughter cells. This process is called:

cytokinesis

What is the force driving all of these transport mechanisms?

diffusion down a concentration gradient

Which of the following best describes osmosis?

diffusion of water from a greater water concentration to a lesser water concentration across a selectively permeable membrane

The ______________ is the subatomic particle with the negative charge.

electron

The intake of materials from the extracellular fluid using vesicles is called

endocytosis

A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.

exocytosis

Passive movement of a solute by a carrier protein is called __________.

facilitated diffusion

Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.

facilitated diffusion

The process by which molecules such as glucose are moved into cells down their concentration gradient with the help of membrane-bound carrier proteins is called

facilitated diffusion

Which of the following is a characteristic of the cell membrane?

fluid mosaic

Which of the following would NOT diffuse through the plasma membrane by means of simple diffusion?

glucose

From the rough endoplasmic reticulum, proteins are often sent to the ______________ for further posttranslational modification:

glycosylation

Diffusion of a substance across the cell membrane is influenced by all of the following EXCEPT: lipid solubility concentration gradient the presence of membrane channels the charge on the molecule

hydrolysis of ATP

A blood cell undergoes crenation when it is placed in a(n) ________ solution.

hypertonic

Which of the following solutions contains the most solute?

hypertonic

Hemolysis may occur when a blood cell is placed into a(n) ________ solution.

hypotonic

Where in a typical eukaryotic cell would you expect to find genes?

in the DNA within the cell's nucleus

The toxin ricin rapidly and completely deactivates the ribosome. It is lethal to humans, because it will:

inhibit translation

The plasma membrane of a healthy cell

is selectively permeable.

If two solutions have the same solute concentration, they are said to be:

isotonic

In general, to maintain homeostasis, the relationship between our intracellular and extracellular fluids should be which of the following?

isotonic to each other

What kinds of molecules cannot easily pass through the lipid bilayer of the cell membrane?

large polar molecules

Which of the following acts as the digestive system of the cell, breaking down materials?

lysosome

A molecule of _______________ contains all the codons needed to produce a particular polypeptide.

mRNA (messenger RNA)

Which of the following is a correct statement about mRNA?

mRNA moves from the nucleus to the cytoplasm following RNA processing. - mRNA undergoes RNA processing in the nucleus and then moves to the cytoplasm for translation.

smooth endoplasmic reticulum

metabolism of lipids The smooth ER also plays a role in synthesizing steroid hormones, absorbing and transporting fats, detoxifying toxins, and breaking down glycogen.

What is the function of the golgi apparatus?

modification and packaging of proteins

A primary active transport process is one in which __________.

molecules move through transport proteins that have been activated by ATP hydrolysis

Which of the following best explains diffusion?

movement of molecules from an area of high concentration to an area of low concentration

Movement of the mRNA molecule from the nucleus to the cytoplasm occurs through

nuclear pores

Proteins that are destined to stay in the cytosol (for use by the cell) are synthesized entirely

on free ribosomes

Which of the following is a form of diffusion?

osmosis

What is the normal direction of calcium transport via the calcium pump described in this animation?

out of the cell, against its concentration gradient

Which pH is more acidic, a pH of 4, a pH of 7, or a pH of 9?

pH of 4

The ________ of a cell membrane indicates how easy it is for substances to cross.

permeability

Which part of the phospholipid bilayer of the cell membrane is hydrophilic?

phosphate heads

What part of a cell membrane is usually in contact with the interstitial fluid?

phosphate heads of phospholipids

Which of the following is a component of the plasma membrane that creates a chemical barrier between the inside and the outside of the cell?

phospholipids

Which of the following is the main component of the cell membrane?

phospholipids

Which of the following can be found in the cell membrane?

phospholipids proteins cholesterol

Which part of the cell is most important for maintaining the homeostasis of the intracellular environment?

plasma membrane

What are the three main parts of a human cell?

plasma membrane, cytoplasm and nucleus

A molecule of water (H2O) is formed by what type of bond?

polar covalent bonds

Formation of hydrogen bonds requires hydrogen atoms and what else?

polar covalent bonds

Which of the following is most likely to move through the cell membrane by facilitated diffusion?

polar molecules

The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____.

primary active transport

Which of the following is NOT required for osmosis to occur? selectively permeable membrane concentration gradient water

production of energy (ATP) by the cell

During which of the following phases does chromatin condense and become chromosomes?

prophase

Which of the following lists, in correct order, the phases of mitosis?

prophase, metaphase, anaphase, telophase

The atomic number of an atom refers to the number of _________________ in an atom.

protons

Which type(s) of subatomic particles can be located within the nucleus of an atom?

protons and neutrons

Which organelle is responsible for synthesizing proteins?

ribosomes

The site of translation is

ribosomes in the cell cytoplasm.

The following 4 images demonstrate different processes molecules use to cross the plasma membrane.

simple diffusion osmosis carrier-mediated facilitated diffusion channel-mediated facilitated diffusion.

onds between carbon and hydrogen atoms (as depicted on the right side of the figure) are generally __________.

single covalent bonds

During RNA processing, alternative splicing can result in

slightly different mRNA transcripts that code for different proteins.

All of the following conditions will increase the rate of diffusion, except one. Which of the following is least likely to increase the rate of diffusion? small molecule size high temperatures higher concentration of molecule

small concentration gradient

Consider sweetened ice tea. Which of the following is a solute?

sugar

What is the cell function of the rough endoplasmic reticulum?

synthesis of proteins

Which of the following correctly states the functions that occur at the rough endoplasmic reticulum?

synthesis of proteins that will be associated with membrane

During splicing

the exons are joined back together

What does this figure depict?

the formation of ions, followed by ionic bonding

What is the energy source used by the calcium pump during its normal operation?

the hydrolysis of ATP

When an ionic bond forms, which part(s) of the atoms are directly involved?

the outermost electrons

Facilitated diffusion differs from ordinary (simple) diffusion in that

the rate of molecular movement can be limited by the number of available carrier molecules.

What is the most significant factor in the formation of a covalent bond?

the sharing of electron pairs between two atoms

The above figure illustrates which of the following descriptions?

the use of a sodium concentration gradient to power the pumping of glucose into the cell

What is the immediate purpose of the energy extracted from ATP in the above figure? (the direct result, not the indirect result)

to generate a sodium concentration gradient

The process of forming mRNA from DNA is called:

transcription

Which parts of atoms can interact (react) to form chemical bonds?

valence electrons

All of the following membrane transport mechanisms are passive processes except diffusion osmosis facilitated diffusion movement of water.

vesicular transport (endocytosis and exocytosis). - Vesicular transport, the process of moving substances into (endocytosis) or out of (exocytosis) the cell requires energy in the form of ATP