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