Which of the functions of a plasma membrane are accomplished by proteins in the membrane?
regulating the flow of materials and allowing interactions with other cells
Which statement best describes the relationship between RNA and DNA?
RNA is a copy of DNA that is used to make proteins.
In which of these cell types would you expect to find a membrane-enclosed nucleus?
fungal cell
Which of the components of the cytoskeleton is much more important to animal cells than to plant cells?
microfilaments
Which cellular structure has the most in common with the nuclear envelope?
plasma membrane
Which of the following biological molecules accomplishes work within the cell?
proteins
Which of the following is a function of the smooth endoplasmic reticulum?
lipid manufacture
What is similar about exporting proteins from a cell and digesting food particles within a cell?
Both processes involve the formation of vesicles
The process of creating and exporting a protein requires many organelles. Which of the following lists these organelles in order?
nucleus, rough ER, vesicle, golgi apparatus, vesicle
How are the jobs of the mitochondrion and the chloroplast related?
Mitochondria and chloroplasts both convert energy from some other form into ATP.
Think of all the structures that prokaryotic cells possess and those that they lack. What is the common feature of most of the missing structures?
Most of the missing structures are enclosed by a membrane.
Thermus aquaticus is a species of archaebacteria that grows in steaming hot springs. What would you expect to find in the plasma membrane of this species?
phospholipids with saturated fatty acid tails
What is one feature all receptor proteins must share?
All receptor proteins must span the cell membrane, having a portion outside the cell and a portion inside.
When can a cell transport a molecule across the cell membrane without expending energy?
When the molecule is more concentrated outside the cell.
Cell A has no membrane proteins at all. Cell B has aquaporin membrane proteins. Both cells are placed in a hypertonic solution. What will happen?
Cell B shrivels faster than cell A
A cell has no membrane proteins at all. Which substance will diffuse across the membrane fastest?
oxygen
If the cytoplasmic fluid of cells in a houseplant were to become very salty, what would happen inside those cells?
The vacuoles would shrivel, but the cells would maintain turgor pressure.
Which of the following would be likely to raise the concentration of calcium ions in a cell?
blocking ATP binding sites
As a cell gets larger, which measurement of the cell increases the fastest?
volume
What do gap junctions, tight junctions, and desmosomes have in common with each other, but not with plasmodesmata?
They are made of protein.
Which of these allows hormones to pass from one plant cell to another?
plasmodesmata
Which type of connection would you expect to find between cells of the blood vessels?
tight junctions
Imagine a candy bar sitting on a table in front of you. Which specific types of energy are present in the candy bar?
heat, chemical, and positional energy
A man wants to build a windmill to generate electricity. What type of energy is the man trying to take from the wind?
movement energy
Which of the following represents an increase in entropy?
smashing a drinking glass
What is the definition of an endergonic reaction?
a reaction where the products have more energy than the reactants
When grilling using charcoal, people often wet the charcoal with lighter fluid first. The lighter fluid catches fire first and eventually sets the coals burning. Why does the lighter fluid light faster than the charcoal?
Setting lighter fluid on fire takes less activation energy than setting charcoal on fire.
Which of these is a correct description of a coupled reaction?
In a coupled reaction, an exergonic reaction provides energy to run an endergonic reaction.
Which of the following reactions could be coupled with the synthesis of ATP from ADP and phosphate?
the breakdown of sugar into water and carbon dioxide
How do competitive inhibitors stop a chemical reaction?
Competitive inhibitors bind in the active site of an enzyme.
Why does feedback inhibition occur at the beginning of a metabolic pathway instead of in the middle?
because all of the initial substrates would still be used up if the pathway were stopped in the middle
The law of conservation of energy states that although the form of energy used remains the same, the total amount of energy changes. True or False?
False
Energy is defined as the capacity to do work. True or False?
True
The burning of sugar is an example of an endergonic reaction, and photosynthesis is an example of an exergonic reaction. True or False?
False
Which of these gives the plasma membrane the ability to block most ions and polar compounds from crossing?
phospholipids
What is the difference between cytoplasm and the cytoplasmic fluid?
The cytoplasm includes the cytoplasmic fluid and also some structures.
You find a population of strange cells in a sample of pond water. You wish to determine first whether they are eukaryotic or prokaryotic. You look for a membrane-enclosed nucleus and don't see one, but sometimes the nucleus is hard to spot without staining. What else could you look for to determine which cell type this is?
organelles
What is the purpose of the cell wall?
support and protection
Which of the components of cytoskeleton are used directly for movement?
microtubules and microfilaments
What is the difference between cilia and flagella?
Cilia are much shorter than flagella.
What is the exact function of DNA?
DNA provides the blueprints for making proteins.
What activity occurs in the nucleolus?
Ribosomes are created in the nucleolus.
Which of these processes is absolutely necessary for all of the others to function?
vesicle transport within the cell
Which of the following is a function of the golgi apparatus?
protein modification
What is the purpose of mitochondria?
Mitochondria produce ATP using the energy in food.
Why is the nucleus considered the control center for the cell?
The nucleus controls which proteins are made and when.
Which of the following is present inside a prokaryotic cell?
ribosomes
Where can the phosphate portion of the phospholipids in a membrane be found?
on the surface, facing the outside liquid or the cytoplasm inside
How does the plasma membrane stop most substances from crossing it?
The non-polar fatty acid tails form a barrier to polar substances.
What is the word for membrane proteins that have carbohydrates attached to them?
glycoprotein
Which membrane proteins increase the rate of chemical reactions?
enzymatic proteins
Which type of transport requires assistance from membrane proteins, but no energy?
facillitated energy
What do channel proteins, aquaporins, and carrier proteins have in common?
They all perform facilitated diffusion.
Which direction is water most likely to move?
Water will move out of a hypotonic solution into a hypertonic solution.
What causes a plant to wilt?
The cells lose turgor pressure.
Some white blood cells in the human body are able to engulf bacteria and destroy them. What should this engulfing process be called?
phagocytosis
Why can't cells the size of golf-balls exist?
A cell that large would not have enough surface area to use in exchanging materials.
Which method of transport can a cell use to bring in molecules without allowing them to pass through the plasma membrane?
receptor-mediated endocytosis
Which of the following scenarios is most similar to desmosomes?
staples holding together two pieces of paper
Which of the following is most like a gap junction?
a nuclear pore
A ball is sitting on top of a shelf. What kind of energy is represented by its height above the ground?
potential energy
You place a pot on the stove and turn the stove on. What kind of energy are you giving to the pot?
kinetic energy
Why is the first law of thermodynamics called "the law of conservation of energy?"
because the first law states that energy can't be created or destroyed
Entropy is a tendency toward _____.
a decrease in order
Where does the energy that life uses to combat entropy come from?
the sun
Plants use sunlight to convert carbon dioxide and water into sugar and oxygen. What is the sunlight providing to the equation?
kinetic energy
Which of the following is true about the reaction of ADP and phosphate to form ATP?
The reaction is endergonic.
How do energy carriers participate in coupled reactions?
Energy carriers can be broken apart to power an endergonic reaction or assembled using energy from an exergonic reaction.
Which of the following is true about catalysts?
Catalysts lower the activation energy of an exergonic reaction.
How is an intermediate best defined?
An intermediate is a product of one reaction that will serve as a reactant in another reaction.
Most enzymes do not work if the temperature is raised too much. Why is this?
