BIOL1406 Lab Midterm Review

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? 6 times 1,000,000 times 6000 times 60 times

1,000,000 times

What is the standard pore size of dialysis tubing? 1000 daltons 10,000 daltons 100 daltons 10 daltons

10,000 daltons

Cola (pH 2) is more acidic than beer (pH 4). How many more hydrogen ions are in solution in cola compared to beer? twice as many twenty times as many 8 times as many half as many 100 times as many

100 times as many

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 two fold 100 fold 20 fold

1000 times

A solution with a pH of 5 is ___________ times more ___________ than a solution with a pH of 8. 3; acidic 100; basic 300; basic 30; basic 10,000; acidic 1000; acidic 3; basic 300; acidic 30; acidic

1000; acidic

What is the standard magnification of the ocular lens?___________________

10x

What are the respective sizes of a virus and a plant cell? 3 mm; 30 mm 30 micrometers; 30 nanometers 30 nanometers; 30 micrometers 3 cm; 30 cm

30 nanometers; 30 micrometers

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. 1,4,3,2,5 4,1,5,2,3 5,4,3,2,1 1,2,3,4,5

4,1,5,2,3

What is the pH of human blood? ______________

7.4

Which species of amoeba did you observe under the microscope? Amoeba gorgonia Amoba proteus Acanthamoeba Entamoeba histolytica

Amoba proteus

QUESTION 9 Which of the following statements regarding enzymes is true? Enzymes prevent changes in substrate concentrations from having an effect on reaction rates. Enzymes increase the rate of reaction. Enzymes are permanently altered by the reactions they catalyze. Enzymes have no effect on the rate of a reaction. Enzymes change the direction of a chemical reaction.

Enzymes increase the rate of reaction.

T/F: Water is a solute.

False

What is the molecular formula for ferricyanide? Fe2(CN) Fe2(CN)3 FeCN Fe(CN)6

Fe(CN)6

Placing phospholipids into an aqueous solution immediately results in their forming a lipid bilayer. What is the driving force causing this ordered arrangement? The phospholipids are very orders in water, and gian freedom of movement by forming a bilayer. Hydrophilic/hydrophobic interactions Phospholipids have a strong affinity for other phospholipids, leading to their self-assembly

Hydrophilic/hydrophobic interactions

What feature of phospholipids makes them amphipathic? They have several interconnected rings. Carbon is much more electronegative than hydrogen. One end is hydrophilic and one end is hydrophobic. One fatty acid is saturated and the other is unsaturated.

One end is hydrophilic and one end is hydrophobic.

Which species of paramecium did you study under the microscope? Paramecium aurelia Paramecium caudatum Paramecium polycarum Paramecium bursaria

Paramecium caudatum

Crossing a membrane by simple diffusion can be distinguished from facilitated diffusion because: Simple diffusion is found only in prokaryotes; facilitated diffusion is found only in eukaryotes. Simple diffusion is not saturable; rates of facilitated diffusion are limited by the number of functional membrane proteins and can be saturated. Simple diffusion does not require energy; facilitated diffusion requires a source of ATP. Simple diffusion can only move material in the direction of a concentration gradient; facilitated diffusion moves materials with, and against, a concentration gradient.

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

Why are the microscopes you use in lab called compound microscopes? They are complex pieces of equipment. They are binoculars rather than oculars. They have a double lens system including the ocular lenses and the objective lenses They have a light source, and a mechanism to concentrate the light source.

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

T/F: Water is polar.

True

What does a spectrophotometer measure? product concentration concentration of reactants enzyme concentration absorbance

absorbance

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

acid

Enzymes influence chemical reactions in living systems by: absorbing water that is released in dehydration synthesis (polymerization). combining with excess H+ to form gaseous waste. affecting the rate at which reactions occur. providing the substrate required for the reaction to occur.

affecting the rate at which reactions occur.

How does an enzyme catalyze a reaction? by supplying the energy to speed up a reaction by increasing the amount of free energy of the reaction by changing the equilibrium of a spontaneous reaction by decreasing the energy of activation for a chemical reaction by decreasing the amount of energy released by a reaction

by decreasing the energy of activation for a chemical reaction

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

coenzyme.

The difference in concentration of a solute across a membrane is called the: net concentration. osmotic pressure. concentration gradient. dynamic equilibrium.

concentration gradient.

Which experimental group serves as the standard for comparison? treatment control placebo variable

control

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

endergonic

Lipase, maltase, and protease are: lipids. carbohydrates. hormones. enzymes.

enzymes.

Which of the following transport processes requires the expenditure of energy? osmosis passive transport facilitated diffusion exocytosis

exocytosis

What is the mechanism by which Euglena move? amoeboid movement and pseudopods extension of cytoskeletal structures flagella cilia

flagella

Which of the following is a common monosaccharide? glycogen fructose cellulose lactose

fructose

Glucose + ATP -> glucose 6-phosphate + ADP What is/are the substrate(s) for this reaction? ADP and glucose glucose and ATP ATP and ADP glucose 6-phosphate

glucose and ATP

The covalent bonds found between monomeric subunits of a polysaccharide are known as: peptide bonds phosphodiester bonds glycosidic bonds ester bonds

glycosidic bonds

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

hydrophilic

Carbohydrates are classified as: hydrophilic substances. hydrophobic substances. amphipathic substances. neither hydrophilic nor hydrophobic.

hydrophilic substances.

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: hypotonic isotonic hypertonic osmotic

hypertonic

A tentative explanation for some observations or some phenomenon is known as a(n): hypothesis. law. theory. scientific method.

hypothesis.

Where would you find amoeba? in aqueous environments on dry rocks in trees in sand

in aqueous environments

When you added NaOH to your substrate during the Biuret test, you increased the acidity of your solution. increased pH. decreased pH. increased the buffering capacity of your substrate.

increased pH.

What test would you perform if you wanted to see if onion extract contained polysaccharides? Benedict's test iodine test Sudan IV test Biuret test

iodine test

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

law

Cholesterol is not soluble in water and is nonpolar. To which class of organic molecules does it belong? lipids proteins nucleic acids carbohydrates

lipids

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? changing substrate concentration changing enzyme concentration decreasing temperature by 5 degrees C. maintaining pH at 6.7

maintaining pH at 6.7

Which of the following organelles enables the Euglena to be photoautotrophic? tonoplast mitochondria chloroplasts lysosomes central vacuole

mitochondria

What is the monomeric subunit of carbohydrates? monosaccharide amino acids fatty acids carboxylic acids

monosaccharide

Cells must produce many different enzymes because: enzymes aare generally ineffective at speeding up reactions. rate of production of enzymes is important in regulating energy production by cells. enzymes are degraded quickly. most cellular reactions require a specific, unique enzyme.

most cellular reactions require a specific, unique enzyme.

Which cellular organelle houses the DNA (unit of genetic information)? Golgi stacks nucleus endoplasmic reticulum lysosomes

nucleus

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? parfocal parcentered resolution compound

parcentered

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

pathogen.

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

peptide bonds

Which bonds form the primary structure of the protein? hydrogen bonds ester bonds ionic bonds peptide bonds

peptide bonds

What is the substrate for the enzyme peroxidase? hydroxylamine guaiacol peroxide water

peroxide

Biological membranes are composed primarily of: glycoproteins. triglyceride bilayers. peptidoglycans. phosholipid bilayers. saccharides.

phosholipid bilayers.

Starch is a(n): lipid protein polysaccharide nucleic acid

polysaccharide

The function of a buffer is to: serve as a physiological base. prevent fluctuations in pH. donate protons. provide anions to living organisms.

prevent fluctuations in pH.

What is the role of the rough endoplasmic reticulum? protein synthesis energy production carbohydrate synthesis lipid synthesis

protein synthesis

The Biuret test is used to detect the presence of which group of macromolecules? nucleic acids carbohydrates proteins reducing sugars lipids

proteins

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

proteins

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

proteins

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

resolution

Which cellular structure, found in both prokaryotes and eukaryotes is responsible for protein synthesis? lysosomes Golgi stacks peroxisomes ribosomes

ribosomes

The aperture of which objective lens is largest? oil immersion lens scanning lens low power lens high power lens

scanning lens

Cell membranes are: completely permeable impermeable selectively permeable semipermeable

selectively permeable

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? chloride silver bromide ferricyanide

silver

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: active transport simple diffusion endocytosis/exocytosis facilitated diffusion

simple diffusion

Substance A is a solute that readily moves across the cell membrane in the direction of its concentration gradient. This is an example of: an active transport pump endocytosis/exocytosis facilitated diffusion osmosis simple diffusion

simple diffusion

Which of the following substances is transported across the cell membrane by ATP requiring transport pumps? (select all that apply) carbon dioxide sodium ions oxygen potassium ions proteins water glucose

sodium ions potassium ions proteins

When viewing a specimen under the microscope, you place your slide on the: platform stage objective lens iris diaphragm

stage

Which statistic serves as a measure of experimental variation (individual variation from one subject to another)? standard deviation P value mean range

standard deviation

Rice would most accurately be classifed as a: protein lipid starch reducing sugar

starch

Which of the following disaccharides is NOT a reducing sugar? lactose sucrose maltose (dextrose) raffinose

sucrose

Competitive inhibitors bind to: carbohydrates. an allosteric site on the enzyme. the substrate the active site of the enzyme

the active site of the enzyme

Which of the following is characteristic of a prokaryotic cell? the lack of ribosomes having a cell wall without a cell membrane the lack of a membrane enclosed nucleus the presence of mitochondria the presence of a nucleus with no DNA

the lack of a membrane enclosed nucleus

which of the following accurately describes the nature of the cell membrane? A single layer of molecules is arranged so that the polar regions are oriented toward the cell interior. Ionically bonded sugars form a double layer that is permeable. 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 molecules of the cell membrane are covalently crosslinked forming a solid structure. The molecules of the cell membrane form a single layer with th epolar regions facing toward and interior of the cell and the hydrophobic regions facing the exterior.

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.

Eukaryotic cells can be larger than prokaryotic cells because: they have more chromosomes and a mitotic process of cell division. their internal membrane system allows compartmentalization of functions, and extra surface area for nutrient exchange and location of enzymes. their DNA is localized in the nucleus whereas protein synthesis occurs in the cytoplasm, separating their competing functions. their plasma membrane has more control over the movement of materials into and out of the cell.

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

Paramecium are heterotrophs. How do they obtain nutrients from their surroundings? by releasing enzymes outside the cell to digest any available food sources in the immediate environment. through their oral grooves. by use of their contractractile vacuoles through the trichocyst

through their oral grooves.

The student's t test can be used: to compare experimental results of all experimental designs. to compare two sample means. to analyze multiple variables. to compare two population means.

to compare two sample means.

When biologists study the internal structure of cells, they would most likely use: phase contrast microscopy. transmission electron microscope. a light microscope. dark field microscopy. a fluorescent microscope.

transmission electron microscope.

Which form of lipid is used to store excess energy that is consumed by mammals? triglycerides phospholipids waxes starch

triglycerides

Of the following reasons for performing science, which best represents the core purpose of scientific investigation? to disprove superstitions. understanding the world around us. to determine ways in which the nature of the universe has changed since its inception. promote rational thinking to improve healthcare.

understanding the world around us.

What inorganic molecule is found in the human body in the highest concentration? water carbon dioxide calcium oxygen

water

Which of the following molecules move across the cell membrane by simple diffusion? Check all that apply. potassium ions water oxygen sodium ions glucose carbon dioxide proteins

water oxygen carbon dioxide