Bio Exam 2 Review

The molecule most directly involved in energy transfer within cells is _____.ATP
Which of the following statements concerning enzymes is true and correct?
-Most enzymes are not proteins.
-An enzyme is very specific in terms of which substrates it can bind.
-Enzymes slow down the rate of chemical reactions.
-An enzyme raises the activation energy of a chemical reaction.
-An enzyme is consumed by the catalytic process.
An enzyme is very specific in terms of which substrates it can bind.
The diffusion of water across a selectively permeable membrane is called _____.osmosis (special case of passive transport)
Ten kilocalories are equivalent to ______ calories.10,000
Which one of the following is an example of osmosis?
-the smell of freshly baked pie spreading throughout a house
-the distant sound of church bells ringing
-food in the refrigerator starting to taste like onions because the onions in the vegetable bin have been stored unwrapped
-the smell of a backed-up sewer coming from a bathroom
-the movement of a drink of water eventually into the cells lining the small intestine
the movement of a drink of water eventually into the cells lining the small intestine
Which one of the following is most similar to the mechanism of an enzyme inhibitor?
-keeping someone from parking by parking in their designated spot
-forgetting to put a cap back on a pen
-changing the tires on a car
-driving the wrong way on a one-way street
-combining new ingredients in a new recipe
keeping someone from parking by parking in their designated spot
The sum total of all the chemical reactions that occur in organisms is called ______.metabolism
A cell that neither gains nor loses water when it is immersed in a solution is ______.isotonic to its environment
An enzyme is a protein that __________.changes the rate of a metabolic reaction without being consumed by the reaction
A kilocalorie is equal to _______.1,000 calories
Calories are units
An animal cell placed in a hypertonic solution will __________.lose water by osmosis and shrivel
(Like fingers in water for long period of time will shrivel up)
In osmosis, water always moves toward the _____ solution, that is, toward the solution with the _____ solute concentration.hypertonic … greater
Anything that prevents ATP formation will most likely ______.result in cell death
A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother’s milk. These molecules probably enter the cells lining the baby’s digestive tract via _____.endocytosis
The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium?active transport
Which of the following is the best example of a substance that contains chemical energy?
-stored electrical charge
-water behind a dam
-food that you eat
-falling off of a cliff
food that you eat
Which is the best definition of energy?the capacity to do work
Which one of the following statements about energy is correct?
-We convert about 99% of our food energy to useful work.
-A leaf falling from a tree represents potential energy.
-Chemical energy is a form of kinetic energy.
-Energy cannot be created or destroyed.
-Entropy is the movement of molecules from areas of higher concentration to areas of lower concentration.
energy cannot be created or destroyed
The mechanism of enzyme action is lower the energy of activation or a reaction
exocytosisA vescle inside the cell fuses with the plasma membrane and releases its contents outside of the cell
facilitated diffusionForm of passive transport.
Molecules move across the plasma membrane using a transport protein.
EndocytosisThe plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell
DiffusionA form of passive transport. Molecules move across the plasma membrane by crossing the lipid bilayer
Active TransportRequires energy from the cell.
Molecules move against their concentration gradient
______ is to eating as ______ is to drinking.Phagocyosis…. pinocytosis
Which component of the following reaction is the substrate?
sucrose + sucrase + water → sucrase + glucose + fructose
Which component of the following reaction is the enzyme?
sucrose + sucrase + water → sucrase + glucose + fructose
The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____.diffusion
With the exception of gametes, a human cell contains _____ chromosomes.46
Most human cancers are __________.caused by an accumulation of mutations
Examples of carcinogensUV light, testosterone, cigarette smoke, fat
_____ is a carcinogen that promotes colon cancer.Fat
The cell cycle is a series of events that occur in which order?G1, S, G2, mitosis, cytokinesis
What name is given to a gene that causes cancer?oncogene
Inheritance of certain genes increases the risk of getting certain cancers; thus, it can be said that ______.predisposition to these cancers is inherited
Most of an organism’s DNA is carried by its ______.chromosomes
All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?Proto-oncogenes are necessary for normal control of cell division.
What is the order of the 4 main stages of mitosis?prophase, metaphase, anaphase, telophase
A cancer cell _____.does not respond to the signals that control cell division
The genes that malfunction and cause a cell to become cancerous usually __________.regulate cell division
Replication of chromosomal DNA occurs __________.before a cell divides
Which of the following best describes cancer cells?
-Proto-oncogenes control their cell division.
-They produce toxic compounds.
-They are more highly differentiated than normal cells.
-They will divide a certain number of times and then stop.
-Controls governing cell division have been altered.
Controls governing cell division have been altered
In sexually reproducing multicellular organisms, the main functions of mitosis are _____.Growth and development;
tissue repair/replacement of damaged cells
What events occur during prophase?chromosomes condense and are attached to spindle fibers; the nuclear envelope breaking down
Cyokinesis______.finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells
During _____, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus.interphase
Looking through a light microscope at a dividing cell, you see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing _____.telophase
Which of the following statements is correct?
-Organisms that undergo asexual reproduction contribute only half of their chromosomes to their offspring.
-Geneticists use the terms “son” and “daughter” to distinguish between cells resulting from cell division.
-The sperm and egg have twice as many chromosomes as the parental cells.
-Meiosis results in gametes that are used in reproduction.
-Asexual reproduction requires the production of eggs and sperm.
Meiosis results in gamees that are used in reproduction
What is produced in meiosis?haploid gametes that are called eggs and sperm
Meiosis and cytokinesis result in the formation of __________.four haploid cells
Accidents can occur in meiosis wherein members of a chromosome pair fail to separate at anaphase. This is called _____.nondisjunction (the resulting gametes will have abnormal numbers of chromosomes)
Orientation of homologous pairs of chromosomes at metaphase I results in alternative arrangements that contribute to genetic variation in offspring. The orientation is called _____.independent assortment
The function(s) of meiosis is/are _____.Reproduction (production of gametes)
Meiosis starts with _____ cells and produces _____ gametes.diploid… haploid
Meiosis is typically accomplished in _____.three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of four haploid gametes.
The _____ separate in meiosis I; the _____ separate in meiosis II.homologous chromosomes … sister chromatids
The process of meiosis accomplishes which of the following choices?
-It produces four haploid cells and allows exchange of genetic material between homologous chromosomes.
-It provides eight haploid gametes and can eliminate chromosomes.
-It allows genetic exchange and eliminates the formation of haploid cells.
-It provides mechanisms for sexual reproduction and eliminates the need for mitosis.
-It provides for formation of four haploid cells and reduces the need for sister chromatids.
It produces four haploid cells and allows exchange of genetic material between homologous chromosomes.
Crossing over is______.the exchange of corresponding portions of homologous chromosomes
Anaerobic respiration produces a maximum of ______ ATP per glucose2
The ultimate source of the energy in food is ______.the sun
Of the metabolic pathways listed below, the only pathway found in almost all organisms is __________.glycolysis
Which of the following metabolic pathways is common to both aerobic and anaerobic processes of sugar breakdown?
-conversion of pyruvic acid to acetyl CoA
-the electron transport chain
-conversion of pyruvic acid to lactic acid
-the citric acid cycle
Humans use the calories they obtain from ______ as their source of
Aerobic metabolism always requires _____.oxygen
Respiration describes the exchange of gases between your blood and the outside air. Cellular respiration ______.produces ATP
What waste product does yeast produce under anaerobic conditions?ethyl alcohol
What is the name of the process in which glucose is converted to pyruvic acid?glycolysis
What is glycolysis?the splitting of sugar, splits 6-carbon glucose into two 3-carbon pyruvic acid molecules
The chemical ingredients needed for photosynthesis are _____ and _____.Carbon dioxide…. water
What must pyruvic acid be converted to before it can enter the citric acid cycle?acetyl CoA
Chemical reactions that require oxygen are called _____ while those that do not require oxygen are considered _____.aerobic… anaerobic
_____ is used as food and _____ is produced as a waste in the overall process of cellular respiration.Glucose… carbon dioxide
Where in a cell does glycolysis occur?cytosol
Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for a buildup of _____.lactic acid
What is the correct sequence of stages in cellular respiration?glycolysis, citric acid cycle, electron transport
_____ is a chemical process that uses light energy from the sun to build organic molecules.photosynthesis
Aerobic cellular respiration generates about ______ ATP from one glucose.38
During photosynthesis in chloroplasts, O2 is produced from _____ via a series of reactions associated with __________.H2O… the water- splitting photosystem
CAM plants conserve water by ______.opening the stomata only at night
What is one reason why plants have accessory pigment molecules, like chlorophyll b and carotenoids?to absorb energy in parts of the electromagnetic spectrum that chlorophyll a cannot
The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why?The Calvin cycle depends on products of the light reactions.
The most important role of pigments in photosynthesis is to __________.capture light energy
In photosynthesis, what is the fate of the oxygen atoms present in CO2? They end up sugar molecules and in water
Through what structure(s) do plants obtain most of their water?roots
The overall function of the Calvin cycle is __________.making sugar
C4 plants conserve water by ______.keeping their stomata closed when the weather is hot and dry
What is the equation for photosynthesis?6 CO2 + 6 H2O → C6H12O6 + 6 O2
Burning biofuels releases CO2 into the atmosphere, contributing to global warming. However, this is at least partially offset by __________.the CO2 absorbed during photosynthesis as the plants grow
The end products of photosynthesis are _____ and _____.glucose … oxygen
If a plant appears blue to us, what wavelength of light is being reflected?blue
Which of these wavelengths is least useful for photosynthesis?green
Why are NASA scientists researching plants as a life support system for long-term space flight?packaged food takes up too much space
What growing conditions are NASA scientists manipulating as they study plants for life support systems?light level, density, color of light, type of plant
If you were gardening on a space station, which of these could you eliminate?soil
Which of the following causes the growth of wasteful side shoots on wheat plants?fluorescent light
Which of the following includes some of the benefits of photosynthesis?
-It enhances the greenhouse effect.
-It is a source of carbon dioxide.
-It is an oxygen source as well as a source of stored energy.
-It stores chemical energy.
-It is a source of oxygen.
It is an oxygen source as well as a source of stored energy.
The “photo-” part of the word “photosynthesis” refers to __________, whereas “-synthesis” refers to __________.the light reactions that occur in the thylakoids … the incorporation of carbon dioxide
When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by other electrons obtained by __________.splitting water
What color is strongly reflected by chlorophyll?green
What is a good reason for using fast-growing trees as fuel?Vigorously growing plants remove a lot of carbon dioxide from the air.
In photosynthesis, plants use carbon from _____ to make sugar and other organic molecules.carbon dioxide