Biology Unit 4
You isolate a cellular structure and determine that it is composed of α-tubulin and β-tubulin. Based on this evidence, you correctly identify this structure as a(n)
Actin filament
The smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make ____.
Cell Membranes
The smooth ER is the primary site for the synthesis of proteins and cholesterol needed to make membranes.
False
Proteins that are synthesized by ribosomes may be further modified within what organelle ?
Golgi complex
The solvent, cohesive, and temperature stabilization properties of water are primarily due to its ____.
Hydrogen Bonds
The surfaces of the leaves of many plants help to reduce water loss because they are not water-permeable. How does the biomolecule that makes up this surface differ from other biomolecules?
It is made up of long chains of fatty acids.
Which organelles contain enzymes that break down old cell parts?
Lysosomes
Identify two structural components of the cytoskeleton, and briefly describe their function(s).
Microtubules- move vesicles and organelles via special attachment proteins. Microfilaments- serve a role in cytokinesis, movement, and changes in cell shape
Which two organelles are responsible for converting energy into forms that can be used by cells?
Mitochondria and chloroplasts
Which of the following store and transmit hereditary information?
Nucleic Acids
Briefly explain the relationship between the surface area and volume of a cell and overall cell size. List two ways in which organisms have successfully "solved" this problem.
Surface area of cell has to be large enough to support metabolism of cell volume
Consider an experiment in which starch is dissolved in a liter of water. Some of the solution is placed into a securely tied dialysis bag. The dialysis bag is placed into a beaker containing distilled water and iodine for 30 minutes. What are the correct answers for the questions below? (Note: Iodine reacts with starch to create a black/purple color.) How do substances enter or leave the dialysis bag?
The dialysis bag is permeable to iodine so it can move into the bag but is not permeable to starch.
Consider an experiment in which starch is dissolved in a liter of water. Some of the solution is placed into a securely tied dialysis bag. The dialysis bag is placed into a beaker containing distilled water and iodine for 30 minutes. What are the correct answers for the questions below? (Note: Iodine reacts with starch to create a black/purple color.) What would happen to the color of the solution in the bag?
The solution in the bag would turn purple as the iodine reacts with the starch.
Use the chart below and your knowledge of enzymes to answer the question. If enzyme C is functioning at 25°C and a pH of 7, under which conditions would the rate of enzyme action probably increase?
The temperature is increased to 30 C and the pH is increased to 8.
The many short appendages that a cell has are called cilia.
True
Upon observing a cell of a grass blade, you notice a prominent sac that occupies a large portion of the cell. Which organelle is this?
Vacuole
Enzymes
affect metabolic reaction rates
the basic unit of proteins
amino acids
DNA is associated with certain proteins, forming a complex called...
chromatin
What type of microscopy uses a laser to excite fluorophores in a thin slice through a cell ?
confocal microscopy
Which strategy is the most effective for larger cells to have an effective surface area to volume ratio?
having thin, finger-like projections
A plant cell is placed in a high solute solution. The cells shrink away from the cell wall. Relative to the cell, the solution surrounding the cell is likely:
hypertonic
vacuoles
large membranous sacs of plants and fungi
What enzyme in the ER lumen catalyze the efficient folding of proteins into proper conformations?
molecular chaperones
Fructose and glucose are both examples of ___.
monosaccharides and six-carbon sugars
What is a characteristic found in both prokaryotic and eukaryotic cells ?
plasma membrane
Which phrase best describes rough ER?
studded with ribosomes
The micrometer (μm) is the most convenient unit for measuring cells
true
The cis face of the Golgi complex is most directly involved in what process ?
Accepting vesicles from the ER
Enzymes increase the rate of a given reaction by lowering what kind of energy?
Activation
Lipids
Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.
Identify the type of cell shown in Figure 3.1.
Eukaryotic
Enzymes called proteases in the ER lumen catalyze folding of proteins into proper conformations.
False
In scanning electron microscopy, an electron beam passes through a very thin slice of a specimen and then falls onto a photographic plate or a fluorescent screen.
False
Peroxisomes are found in large numbers in cells that synthesize, store, and degrade lipids, and one of their functions is to break down protein molecules.
False
Proteins made on ribosomes may be further modified within which organelle?
Golgi complex
An enzyme in your digestive system works on the disaccharide lactose to break it in two. What is the likely name of this enzyme?
Lactase
Which of the following bio-molecules are major energy sources for cells?
Lipids
Plants lack organ systems for disposing of toxic metabolic waste products. Their cells' vacuoles are similar to which animal cell organelle?
Lysosomes
Which of the following is found in every nucleotide?
Phosphate Group
Bacteria are best classified as which type of cell?
Prokaryotic
What does the nucleolus, within the nucleus, synthesize?
Ribosomal RNA
Which lipid type does not have fatty acid tails and have 4 fused rings?
Steroids
Microfilaments are linked with one another and with other proteins by linker proteins.
True
Cellulose is ____.
a polysaccharide found in cell walls of plants
Glucose
a six-carbon sugar
Evidence that all living cells have a common origin is best illustrated by...
basic similarities in cell structure and chemistry
What technique is used to separate different part of cells so that they can be studied by both physical and chemical methods?
cell fractionation
The smooth ER is the primary site for the synthesis of phospholipids and cholesterol needed to make____
cell membranes
Which organelles are unique to plant cells?
chloroplasts
Name the part of the cell outside the nucleus.
cytoplasm
During an infection, white blood cells travel to the infected site and phagocytize the pathogens. After phagocytosis, primary lysosomes fuse with the phagocytic vesicle to form a larger vesicle called a secondary lysosome. The purpose is to...
degrade the pathogens into components, which the cell recycles/uses an energy source
plastids
encloses an internal thylakoid membrane
A basal body anchors what part of a cell?
flagellum
Necessary for a cell to maintain its function and growth...
food
Nucleotide
found in DNA and RNA
nucleolus
granular body within an organelle which consists of RNA and protein
Enzymes only work with certain substrates. If a certain enzyme only works with a certain substrate, it is because the enzyme
has a particular shape that matches the substrate
You watch a scientist dissolve some sugar in a liter of water and then place some of this solution into a dialysis bag, tying both ends shut. The she places the bag into a beaker of distilled water. What word best describes the solution outside of the bag?
hypotonic
The ratio of the size of the image seen w/ the microscope to the actual size of the object is called:
magnification
lysosome
membranous sacs in animals
Which of the following is a key component of the cytoskeleton?
microtubules
Intermediate filaments are most closely associated with
microvilli
What organelles plays an important role in apoptosis, or programmed cell death?
mitochondria
Which organelles supply energy to the cell?
mitochondria
The cytoplasm of human cheek cells is 96% water and 4% NaCl (salt.) A scientist removes some of your cheek cells and places them in an solution that is 30% NaCl. Which direction of net water flow would result?
net water flow out of the cell
the basic unit of DNA
nucleotide
the basic unit of RNA
nucleotide
specialized structures within a living cell are known as...
organelles
Which process occurs inside the chloroplasts?
photosynthesis
What is one cellular characteristic found in all cells both prokaryotic and eukaryotic?
plasma (cell) membrane
A cell is surrounded by which distinctive surface membrane ?
plasma membrane
Phospholipids
principle components of the cell membrane
If a bacterial toxin destroys ribosomes, what cellular activity will be affected first?
protein synthesis
What does nucleolus, within the nucleus, synthesize ?
ribosomal RNA
Rough ER
ribosomes stud its outer surface
microfilaments
rodlike structures consisting of actin
The accompanying image is the product which type of microscope?
scanning electron microscope
A friend goes to get a blood transfusion. Blood cells are 95% water. You notice the nurse hanging a bag of 60% glucose to inject into your friend instead of blood. You yell "stop!" What did you think would happen to your friend's blood cells if they were transfused with the sugar water instead of blood
they would crenate
What is the purpose of the cristae of the inner membrane of mitochondria?
to break down nutrients
What is the primary function of mitochondria?
transformation of energy
One of the ways that food can be preserved is by heavily salting it so that bacteria cannot live upon the food. What causes the bacteria to die in an extremely salty environment?
water moves out of bacteria by osmosis
Consider an experiment in which starch is dissolved in a liter of water. Some of the solution is placed into a securely tied dialysis bag. The dialysis bag is placed into a beaker containing distilled water and iodine for 30 minutes. What are the correct answers for the questions below? (Note: Iodine reacts with starch to create a black/purple color.) How would the mass of the bag change after a few hours?
After several hours, the mass of the bag should increase as water moves by osmosis from the lower concentration outside the bag to the higher concentration (hypertonic solution).
Briefly compare prokaryotic and eukaryotic cells. Identify three ways that differences between eukaryotes and prokaryotes impact cell function.
Both have cytoplasm, ribosomes, DNA, RNA, and plasma membrane. Difference is only eukaryotes have membrane bound organelles. Eukaryotes generate more ATP molecules
Proteins are responsible for which of the following functions?
Building blocks of both DNA and RNA
What are the four most common elements found in Biological Macromolecules?
C,H,O,N
Which molecule is incorrectly matched with its monomer?
Carbohydrate: polysaccharide
Which of the following biomolecules are major energy sources for cells?
Carbohydrates
Any substance that accelerates the rate of a chemical reaction is called a(an)
Catalyst
Consider an experiment in which starch is dissolved in a liter of water. Some of the solution is placed into a securely tied dialysis bag. The dialysis bag is placed into a beaker containing distilled water and iodine for 30 minutes. What are the correct answers for the questions below? (Note: Iodine reacts with starch to create a black/purple color.) Would there be a color change in the water-iodine solution?
The water iodine solution has no color change.
Some protists live in freshwater. Paramecium have contractile vacuoles, which act to pump water out of the cell. Why?
There is a higher solute concentration inside so water is moving into the cell constantly