Chapter 4 bio

Most cellular work is accomplished by the consumption of __________, which energizes molecules by __________ them. View Available Hint(s) for Part A substrates ... phosphorylating ATP ... phosphorylating coenzymes ... activating enzymes ... activating

ATP........ phosphorylating

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____. View Available Hint(s) for Part A actively pump water back out of their cells to counter its inflow due to osmosis actively pump salt back out of their cells to counter its inflow due to osmosis synthesize membranes that are impermeable to substances that upset osmotic balance actively pump water back into their cells to counter its loss due to osmosis

Actively pump water back into thier cells to counter its loss due to osmosis

Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____. View Available Hint(s) for Part A B ... the diffusion gradient there is steeper B ... the oxygen molecules inside cell B have a higher kinetic energy A ... its membrane transport proteins will not be saturated A ... the diffusion gradient there is shallower

B.... The diffusion gradient there is steeper

Which of the following is NOT an example of an organelle found in animals? View Available Hint(s) for Part A A.cell wall B.lysosomes C.nucleus's D.endoplasmic reticulum

Cell wall

The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____. View Available Hint(s) for Part A spontaneous combustion diffusion active transport plasmolysis

Diffusion

Which of the following components is external to the plasma membrane? A.extracellular matrix B.chloroplasts C.cytoskeleton D.cilia

Extracellular matrix

Use the graph and your knowledge of enzymes to identify the three true statements about enzymes. Reactants cannot convert to products without an initial input of energy to start the reaction. By binding to reactant molecules, enzymes make it easier for the bonds in the molecules to break apart. Enzymes lower the overall energy input needed for a reaction to occur. Only reactions that are controlled by enzymes require activation energy. Chemical reactions cannot occur without enzymes.

First 3

A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum that was eventually used to build a cell's plasma membrane: the protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the __________. View Available Hint(s) for Part A A.nucleus B.mitochondria C.Golgi apparatus D.smooth endoplasmic reticulum

Golgi Apparatus

Mitochondria and chloroplasts are similar in that they both __________; however, they are different in that only chloroplasts, and not mitochondria, __________. A.have many internal membranes that increase their internal surface area ... are found in plants B.have an internal 9 + 2 arrangement of microtubules ... also have centrioles C.deal with energy transformations ... are found only in eukaryotes D.have a double membrane ... carry out photosynthesis

Have a double membrane..... carry out photosynthesis

Part complete In the process of osmosis, water displays a net movement from an area of __________ water concentration to an area of __________ water concentration. View Available Hint(s) for Part A lower ... higher lower ... lower higher ... lower higher ... equal

Higher ...... lower

Why doesn't the antibiotic penicillin harm humans? View Available Hint(s) for Part A Penicillin attacks the nervous system. Penicillin attacks plasma membranes. The dosage given to kill bacteria is too low to harm humans. Human cells do not have cell walls.

Human cells do not have cells walls

The plant cell wall View Available Hint(s) for Part B A. is very similar to the animal cell wall. B.regulates the composition of the cytoplasm. C.is found just inside the plasma membrane. D. makes food by converting light energy to chemical energy. E. is a protective structure made of cellulose fibrils.

Is a protective structure made of cellulose fibrils

The maximum size of a cell is limited by _____. View Available Hint(s) for Part A A.the materials needed to build it B.the number of organelles that can be packed inside C.its need for enough surface area to make exchanges with its environment D.the amount of flexibility it needs to be able to move

It's need for enough surface area to make exchanges with its environment

A disease called primary ciliary dyskinesia is characterized by abnormal ciliary movements. In these cilia, microtubule functioning is disrupted due to microtubules missing an essential component. This disease could be caused by __________. View Available Hint(s) for Part A A.lack of integrins B.too many integrin proteins C.lack of actin proteins D.lack of dynein proteins

Lack of dynein proteins

Which organelle plays a role in intracellular digestion? lysosome plasmodesma ribosome Golgi apparatus chloroplast

Lysosome

Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell? View Available Hint(s) for Part A A.Mitochondrion. B.Central vacuole. C.Chloroplast. D.Golgi apparatus. E.Plasma membrane.

Mitochondrion

In active transport, View Available Hint(s) for Part A no energy input is required from the cell. molecules move across the plasma membrane against their concentration gradient. a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell. the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. molecules move across the plasma membrane by crossing the lipid bilayer directly, rather than by using a transport protein.

Molecules move across the plasma membrane against thier t concentration gradient

The synthesis of an amino acid follows this pathway: precursor A → intermediate B → amino acid C. Each reaction is catalyzed by a different enzyme. This metabolic pathway is controlled by feedback inhibition with amino acid C inhibiting the conversion of precursor A to intermediate B. Amino acid C acts as a _____ of the first enzyme in the pathway. View Available Hint(s) for Part A competitive inhibitor substrate catalyst noncompetitive inhibitor

Noncompetitive inhibitor

The plasma membrane is selectively permeable. Which of the following can pass freely through the membrane with no assistance? View Available Hint(s) for Part A glucose and lactose oxygen and carbon dioxide sodium and hydrogen ions starch and cellulose

Oxygen and carbon dioxide

You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls made of cellulose. This new organism is most likely a(n) __________. View Available Hint(s) for Part A animal bacterium plant prokaryote

Plant

Which of the following would distinguish a bacterial cell from an animal cell? A.presence of a plasma membrane B.production of proteins C.replication of DNA D.presence of a cell wall

Presence of a cell wall

Which curve shows the course of the reaction in the presence of an enzyme--the black curve or the red curve? Which line represents the activation energy for that reaction--a, b, or c? black curve; line a black curve; line b black curve; line c red curve; line a red curve; line b red curve; line c

Red curve ;line b

Which of the following structure(s) is/are found in prokaryotic cells? View Available Hint(s) for Part A endoplasmic reticulum nucleus mitochondria ribosomes

Ribosomes

Which of the following is a function of the rough endoplasmic reticulum? synthesizing receptor proteins synthesizing steroid hormones detoxifying drugs storing calcium ions

Synthesizing receptor proteins

Which of the following is the most likely consequence for a cell lacking functional lysosomes? View Available Hint(s) for Part A A.The cell dies because its ATP-synthesizing mechanisms are missing. B.The cell becomes crowded with undigested wastes. C.The cell dies from a lack of enzymes to catalyze metabolic reactions. D.The cell is unable to grow to a mature size and always remains small.

The becomes crowed with undigested wastes

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? View Available Hint(s) for Part A The intestinal cells are bound together by tight junctions. The intestinal cells are bound together by plasmodesmata. The intestinal cells are fused together into one giant cell. The intestinal cells are bound together by gap junctions.

The cells are bound together by tight junctions

Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. What really drives osmosis? View Available Hint(s) for Part A the difference in water concentration across a selectively permeable membrane the first law of thermodynamics the difference in sugar or ion concentration across a selectively permeable membrane the difference in the height of water columns on either side of a selectively permeable membrane

The difference in water concentration across a selectively permeable membrane

Part complete What controls the net direction of the movement of oxygen molecules in passive transport? View Available Hint(s) for Part A the size of the oxygen molecule the amount of energy available to transport oxygen the type of cell to or from which the oxygen molecule is moving the direction of the oxygen concentration gradient

The direction of the oxygen concentration gradient

What is the relationship between the Golgi apparatus and the plasma membrane? View Available Hint(s) for Part A The membranes of the Golgi apparatus and the plasma membrane are continuous. The plasma membrane stops the products of the Golgi apparatus from leaving the cell. The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane. The Golgi apparatus produces the lipids that make up plasma membranes. Submit

The finished product of the Golgi apparatus may leave the cells through vesicles that fuse with the plasma membrane

One function of the central vacuole in plant cells is facilitating cell growth: the central vacuole absorbs water and increases in size, expanding the volume and size of the plant cell while doing so. Animal cells, however, do not grow by this method. What is an essential difference between animal and plant cells that could explain how a plant cell can withstand the internal pressure caused by this expansion of the central vacuole? View Available Hint(s) for Part A The plant cell wall provides a rigid structure, preventing cell rupture. Plant cells grow at a slower rate than animal cells. Animal cells have a similar organelle that produces the same effect as the central vacuole. Plant cells cannot divide.

The plant cell wall provides a rigid structure preventing cell rupture

Taq polymerase is an enzyme isolated from the organism Thermophilus aquaticus. This organism has been found living in the hot springs of Yellowstone National Park. This enzyme is used to copy human DNA from crime scenes. Most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? View Available Hint(s) for Part A Nothing should be altered. The temperature should be raised. The enzyme will not work on human DNA. The pH should be decreased.

The temperature should be raised

Part complete A pharmaceutical company wishes to focus on an enzyme to develop new medications. What type of initial study would be of the greatest benefit? View Available Hint(s) for Part A Studying the structure of an enzyme would help pharmaceutical companies determine the enzyme's substrate. Studying the structure would help pharmaceutical companies create enzymes that are not destroyed during reactions. Knowing the structure of enzymes may make it possible to design enzymes that raise the activation energy above that of the spontaneous reaction to allow more efficient drug synthesis. Understanding the enzyme's structure would help pharmaceutical companies design molecules that fit to the binding site and alter activity.

Understanding the enzymes structure would help pharmaceutical companies design molecules that fit to the binding site and alter activity

Recall from Chapter 4 that phospholipids have two parts: a polar head and two nonpolar tails. In an oil-based, nonpolar environment, phospholipids would arrange themselves so that they __________. View Available Hint(s) for Part A would never associate but instead would remain as individual molecules completely dissolved in the oil would not pack together at all would pack more tightly together than they would in a watery environment would stay together but in a reverse orientation, with their tails projecting outward

Would stay together but in a reverse orientation, with their tails projecting outward

In eukaryotic cells the first step in protein synthesis is the _____. A.translation of a DNA nucleotide sequence into a sequence of amino acids B.transferring of information from DNA to messenger RNA C.translation of an RNA nucleotide sequence into a sequence of amino acids removal of introns from RNA and the stitching together of exons D.linking of nucleotides to form a polypeptide

transferring of information from DNA to messenger RNA