Lab Exam Lab Review Questions
As what molecule do plants store glucose?
Starch
What kind of microscope would be used to study a whole or opaque object?
Stereomicroscope (dissecting microscope)
Which type of microscope used to view a virus that is 50 nm in size
Stereomicroscope (dissecting microscope) b/c it sees whole small organisms in 3D
Global deforestation has decreased the amount of plants on Earth available to run photosynthesis. What impact is this having on the pH of the oceans?
The pH of the oceans are falling and becoming more acidic because there's too much carbon dioxide dissolving into the water.
scanning electron microscope
a microscope that produces an enlarged, three-dimensional image of an object by using a beam of electrons rather than light
hypothesis
a tentative, testable statement or prediction about what has been observed
scientific theory
a well-tested concept that explains a wide range of observations
What color of light is absorbed by carotenes?
blue, green, violet
Prokaryotic cell
cell that does not have a nucleus or other membrane-bound organelles.
What molecule is associated with plant cell walls?
cellulose
List the various photosynthetic pigments that are found in leaves
chlorophyll a and chlorophyll b and carotenes
stereomicroscope (dissecting microscope)
designed to study entire objects in 3D at low magnification
what kind of protein is lactase, the biomolecule that speeds up the breakdown of lactose?
enzyme.
cell theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
what do scientists do when they first begin to study a specific subject?
make observations
compound light microscope
microscope that allows light to pass through a specimen and uses two lenses to form an image, used for examining small or thinly sliced sections of objects under higher magnification
what do we call the sample that lacks the factor being tested and goes through all the experimental steps?
negative control
total magnification
objective lens x ocular lens
What are the steps of the scientific method?
observation, hypothesis, experiment, conclusion
what is the name used for plant fats?
oils
what kind of bond forms during a dehydration synthesis reaction involving two amino acids?
peptide bond
What two things are found in the nucleus of a eukaryotic cell?
DNA and RNA
Since enzymes are specific for certain substrates and often have similar names, what is the name of the enzyme used in tube 3 of the catalase activity experiment that facilitates the breakdown of sucrose?
Degradation Enzymatic Reaction
What word describes the loss of an enzyme's original shape and ability of its active site to function?
Denatured
If the amount of light passing through the condenser needs to be decreased, what microscope part should be adjusted?
Diaphragm
What is the movement of molecules from an area of higher to lower concentration called?
Diffusion
What must be present to successfully break down fats during digestion?
Emulsifier. Lipase enzymes.
What happens to enzyme activity if the temperature increases slightly?
Enzyme activity increases with heat
What did measuring the bubble column heights in all the experimental procedures indicate?
Enzyme activity.
Parts of a microscope
Eyepiece or ocular lenses, low-power objective, high-power objective, nosepiece, bodytube, coarse adjustment, fine adjustment, stage, stage clips, diaphragm, light source, base
What is the transport of substances across a biological membrane from an area of higher concentration to an area of lower concentration with the help of a transport molecule
Facilitated diffusion
After enjoying a meal of fish and chips, you notice your shirt has an oily stain on it. why won't the oily stain come out when you dab at it with a wet napkin?
Fats are non polar, do not mix with water
If a slide is being viewed with the high-power objective, which adjustment knob should be used to sharpen the focus?
Fine-adjustment knob
What molecule is most commonly broken down during cellular respiration and fermentation?
Glucose
What color of light is not absorbed by green plants?
Green wavelengths of white light
what kind of reaction adds water to break large biomolecules into subunits?
Hydrolysis reaction
What kind of solution causes crenation (shriveling) to happen to red blood cells?
Hypertonic solution
What kind of solution causes chloroplasts to be pushed outward against the cell wall (turgor)?
Hypotonic solution
What kind of solution causes hemolysis (bursting) to happen to red blood cells?
Hypotonic solution
What symbol represents the change that occurs in a chemical reaction?
In a chemical equation, reactants are written on the left hand side of the equation and the products on the right. The arrow is used to show the direction of the reaction.
Does water move into or out of cells that are placed in a hypotonic solution?
Into
What does a shift in pH (too high or too low) do to an enzyme that will influence its activity?
It may denature the enzyme
If amylase is added to a sample of potato and you test it with Benedict's reagent 10 minutes later, what do you expect the results of the test to be?
It will turn orange and be positive because starch is broken down in glucose
Which objective should be in place when the microscope is put away?
Scanning
Ovarian follicle cells produce estrogen, which is a steroid. What organelle will be present in abundance so that the follicle cells might perform this function?
Smooth Endoplasmic reticulum
all organisms are made of cells is a
theory
List the reactants necessary for photosynthesis
water, carbon dioxide, ATP, and NADPH
3.4 liters equals how many ml?
3400 ml
90*F equals how many degrees Celsius?
37.2* C
If the total magnification of a slide is 400x and the ocular lenses are 10x, what is the magnifying power of the objective being used?
4000x
What structures carry out protein synthesis?
Ribosomes and the rough ER
If Euglena are swimming to the left, which way should you move your slide to keep them in view?
Right
Contact lens solution is described as a sterile, buffered, isotonic aqueous solution. Explain the importance of the adjectives buffered and isotonic to the person buying the solution.
Buffered- The solution is acidic so it wont denature any cells Isotonic- Prevents shriveling/enlargement of lense.
What is present in human blood that ensures blood pH is maintained at about 7.4?
Buffers
If you test a solution with biuret reagent and the solution turns purple, what does this indicate?
There is protein present
If cells produce more catalase, will there be more or less water and oxygen produced from the breakdown of hydrogen peroxide by catalase?
More
What technique was used to separate the leaf pigments?
Paper chromatography. Each molecule travels at a different speed when pulled along the piece of paper toweling by the solvent. The lightest particles, which are not necessarily the lightest colored particles, move more quickly and a greater distance than the heavier particles.
What word describes a microscope that remains in focus when the objective lenses are changed?
Parfocal
What word describes the pH at which the speed of a reaction involving an enzyme occurs best?
Optimum pH
What is the movement of water across the plasma membrane called?
Osmosis
Does water move into or out of cells that are placed in a hypertonic solution?
Out
What gas is released during the light reactions of photosynthesis?
Oxygen
What cellular organelle contains catalase and is present in all plant and animal organs?
Peroxisomes (break down hydrogen peroxide to water and oxygen)
If threads are layered from top to bottom, brown, green, red, which layer will come into focus first if you are using the microscope properly?
Brown
What purpose did the tube containing water and hydrogen peroxide serve in the catalase activity experimental procedure?
A negative control
If two fatty acids, glycerol, and a phosphate group undergo a dehydration reaction, what biomolecule forms?
Phospholipids
How to convert Fahrenheit to Celsius
(F-32)/1.8
880 mm equals how many m?
0.88 m
19 mm equals how many cm?
1.9 cm
transmission electron microscope
An electron microscope used to study the internal structure of thin sections of cells
If net photosynthesis is 15mm/10min and cellular respiration is 1.5mm/10min, how much is gross photosynthesis?
16.5mm/10min.
2700 mg equals how many grams?
2.7 g
If a solution has more hydrogen ions than hydroxide, is the solution acidic or basic?
Acidic
What is the name of the location on an enzyme where its substrate or substrates bind?
Active site
What is the process of moving molecules across a cellular membrane through the use of cellular energy
Active transport
What cellular structures are common to prokaryotic and eukaryotic cells?
All cells have a plasma membrane, ribosomes, cytoplasm, and DNA.
If you want to test a sample for the presence of glucose, what reagent should you use?
Benedicts Solution
What color does iodine turn in the presence of starch?
Black-blue
When CO2 combines with H2O, what is the product that makes phenol red turn yellow?
Carbon Dioxide, CO2 (it dissolves in the solution and creates carbonic acid)
Based on distance traveled up the chromatography paper, which pigment is the most nonpolar pigment?
Carotenes
What did the negative control tube lack when the effect of enzyme concentration was studied?
Catalase
What regulates the movement of molecules in and out of the cytoplasm?
Cell membrane
What plant cell organelle carries out photosynthesis?
Chloroplast
What organelle, present in eukaryotic photosynthetic organisms, is the location of photosynthesis?
Chloroplasts
What kinds of biomolecules are insoluble in water but soluble in alcohol or ether?
Lipids/fats
To properly measure 20 ml of water, what must be at the 20 ml mark of the graduated cylinder?
Meniscus
What energy (ATP) producing organelle is found in animal and plant cells?
Mitochondria
What organelle, present in animal and plant cells, completes the breakdown of glucose during cellular respiration?
Mitochondria
How to convert Celsius to Fahrenheit
Multiply by 1.8 than add 32
If maltose undergoes hydrolysis, what subunits result?
Nucleotides
What is the name for the lenses located near the eye?
Ocular lenses
If you test an unknown substance with the biuret reagent and it turns purple, what is present?
Protein
Are the substrates in an enzymatic reaction reactants or products?
Reactants
If a solution contains a large amount of glucose, what color will the Benedict's reagent become?
Red
Where is CO2 reduced during the Calvin cycle reactions?
The stroma of the chloroplast
CO2 (carbon dioxide) is broken apart during photosynthesis. Where will the carbon molecules end up?
They become glucose.
What is the importance of the light reactions of photosynthesis since they do not directly produce energy-rich carbohydrates?
They produce chemical energy in the form of NADPH and ATP
During photosynthesis, where is water split and oxygen released?
Thylakoid space
What will plants and animals use the gas released from photosynthesis for?
To breathe
In the experimental procedure on the effect of pH on enzyme activity, which tube contained water with an acidic pH?
Tube 1- 20 ml of water adjusted to pH 3