BIOL1406 Lab Midterm Review

Term which means that if an object is centered with the low power objective, it is centered when you switch to the high power objective?

parcentered

Paramecium are heterotrophs. How do they obtain nutrients from their surroundings?

through their oral grooves.

A tentative explanation for some observations or some phenomenon is known as a(n):

hypothesis.

What inorganic molecule is found in the human body in the highest concentration?

water

What test would you perform if you wanted to see if onion extract contained polysaccharides?

iodine test

The covalent bonds found between monomeric subunits of a polysaccharide are known as:

glycosidic bonds

Substance A is a solute that readily moves across the cell membrane in the direction of its concentration gradient. This is an example of:

simple diffusion

What is the molecular formula for ferricyanide?

Fe(CN)6

Glucose + ATP -> glucose 6-phosphate + ADP

What is/are the substrate(s) for this reaction?

glucose and ATP

Competitive inhibitors bind to:

the active site of the enzyme

Which of the following is characteristic of a prokaryotic cell?

the lack of a membrane enclosed nucleus

What is the mechanism by which Euglena move?

flagella

Of the following reasons for performing science, which best represents the core purpose of scientific investigation?

understanding the world around us.

The function of a buffer is to:

prevent fluctuations in pH.

Which of the following is a common monosaccharide?

fructose

Which of the following disaccharides is NOT a reducing sugar?

sucrose

Placing phospholipids into an aqueous solution immediately results in their forming a lipid bilayer. What is the driving force causing this ordered arrangement?

Hydrophilic/hydrophobic interactions

Cell membranes are:

selectively permeable

When the products of a reaction are at a higher energy level than the reactants, the reaction is:

endergonic

What are the respective sizes of a virus and a plant cell?

30 nanometers; 30 micrometers

When biologists study the internal structure of cells, they would most likely use:

transmission electron microscope.

The Biuret test is used to detect the presence of which group of macromolecules?

proteins

which of the following accurately describes the nature of the cell membrane?

the molecules form a double layer with the polar regions facing the cell interior and the otuside of the cell, and hydrophobic regions forming the interior of the cell membrane.

The difference in concentration of a solute across a membrane is called the:

concentration gradient.

When using microscopy, the ability to see two items as separate and discrete entities is:

resolution

Eukaryotic cells can be larger than prokaryotic cells because:

their internal membrane system allows compartmentalization of functions, and extra surface area for nutrient exchange and location of enzymes.

A compound that tends to release H+ ions in solution (i.e. a proton donor) is classified as a(n):

acid

Stomach acid may have a pH as low as 2. Seawater has a pH of 8. How much higher is the hydrogen ion concentration in stomach acid compared with seawater?

1,000,000 times

The portion of a phospholipid that contains the phosphate group has one or more electrical charges. That makes this region of the molecule:

hydrophilic

When you added NaOH to your substrate during the Biuret test, you

increased pH.

Which of the following substances is transported across the cell membrane by ATP requiring transport pumps? (select all that apply)

sodium ions

potassium ions

proteins

A substance is soluble in the lipid bilayer, and moves across the membrane from a point of higher concentration to a point of lower concentration. This process is known as:

simple diffusion

Cells must produce many different enzymes because:

most cellular reactions require a specific, unique enzyme.

Which species of paramecium did you study under the microscope?

Paramecium caudatum

Where would you find amoeba?

in aqueous environments

Cola (pH 2) is more acidic than beer (pH 4). How many more hydrogen ions are in solution in cola compared to beer?

100 times as many

Cholesterol is not soluble in water and its non-polar. To which class of organic molecules does it belong?

lipids

Which of the following molecules move across the cell membrane by simple diffusion? Check all that apply.

water

oxygen

carbon dioxide

A sample of cells is placed into a salt solution. The cells shrink and the membrane is distorted. Relative to the cell, the solution is probably:

hypertonic

What is the standard magnification of the ocular lens?___________________

10x

Which cellular structure, found in both prokaryotes and eukaryotes is responsible for protein synthesis?

ribosomes

A solution with a pH of 5 is ___________ times more ___________ than a solution with a pH of 8.

1000; acidic

The covalent bonds found between individual amino acids of a protein or polypeptide are known as:

peptide bonds

Rice would most accurately be classifed as a:

starch

Which component of a cell membrane is likely to function as a receptor in cell-to-cell signaling?

proteins

The aperture of which objective lens is largest?

scanning lens

When the explanation for a group or set of observations is strongly supported and virtually irrefutable, that explanation becomes a(n):

law

Starch is a(n):

polysaccharide

Which of the following transport processes requires the expenditure of energy?

exocytosis

What is the standard pore size of dialysis tubing?

10,000 daltons

How does an enzyme catalyze a reaction?

by decreasing the energy of activation for a chemical reaction

Which species of amoeba did you observe under the microscope?

Amoba proteus

What is the pH of human blood? ______________

7.4

Which experimental group serves as the standard for comparison?

control

What feature of phospholipids makes them amphipathic?

One end is hydrophilic and one end is hydrophobic.

In the experiment with diffusion in a solid, what was the ion in the center well with which the other ions reacted to form precipitation bands?

silver

Which of the following membrane constituents is most likely to determine the selectivity of the cell membrane?

proteins

Why are the microscopes you use in lab called compound microscopes?

They have a double lens system including the ocular lenses and the objective lenses

Which cellular organelle houses the DNA (unit of genetic information)?

nucleus

Egg yolks have a pH of 5.6; milk has a pH of 6.6; orange juice has a pH of 3.6; and water has a pH of 7. What is the difference in hydrogen ion concentration between milk and orange juice?

1000 times

Which statistic serves as a measure of experimental variation (individual variation from one subject to another)?

standard deviation

Carbohydrates are classified as:

hydrophilic substances.

What does a spectrophotometer measure?

absorbance

Which of the following organelles enables the Euglena to be photoautotrophic?

mitochondria

T/F: Water is polar.

True

Which form of lipid is used to store excess energy that is consumed by mammals?

triglycerides

Biological membranes are composed primarily of:

phosholipid bilayers.

Crossing a membrane by simple diffusion can be distinguished from facilitated diffusion because:

Simple diffusion is not saturable; rates of facilitated diffusion are limited by the number of functional membrane proteins and can be saturated.

The organic nonprotein portion of an enzyme that is required for proper function is a(n):

coenzyme.

When viewing a specimen under the microscope, you place your slide on the:

stage

T/F: Water is a solute.

False

The student's t test can be used:

to compare two sample means.

Lipase, maltase, and protease are:

enzymes.

What is the substrate for the enzyme peroxidase?

peroxide

An organism that causes disease in its host is known as a(n):

pathogen.

What is the role of the rough endoplasmic reticulum?

protein synthesis

Arrange the following steps of the scientific method in the correct order.

1. A hypothesis is developed.

2. Experiments are conducted.

3. The hypothesis is supported or rejected.

4. Observations are made.

5. The experimental setup is designed.

4,1,5,2,3

What is the monomeric subunit of carbohydrates?

monosaccharide

Which bonds form the primary structure of the protein?

peptide bonds

Salivary amylase is a human enzyme that degrades starch. The pH optimum of salivary amylase is 6.7. Which of the following would have no effect on reaction rate?

maintaining pH at 6.7

Enzymes influence chemical reactions in living systems by:

affecting the rate at which reactions occur.