question

An atom is converted into an ion by adding or removing ___________________.

answer

electrons :When electrons are added or removed from an atom, the charge of the atom changes and the atom becomes an ion.

question

The positive particle in the atom is the ...

answer

proton :Protons are positively charged.

question

How many electrons does a neon atom have in its second shell?

answer

8 :This second and third shells can hold up to 8 electrons.

question

Which is the biggest? Proton Neutron Atom Electron

answer

Atom

question

The negative particle in the atom is the ...

answer

electron

question

What would be the charge of a beryllium atom that has a full outer shell? +1 no charge -1 +2

answer

+2

question

Fluorine, F, has an atomic number of 9 and an approximate atomic mass of 19. What would be the charge of fluorine that has a full outer shell? +2 +1 -1 no charge

answer

-1

question

Negatively charged particles are found where in an atom? In the nucleus In a single layer outside the nucleus In multiple layers outside the nucleus Both inside and outside the nucleus

answer

In multiple layers outside the nucleus

question

Beryllium, Be, has an atomic number of 4 and an atomic mass of approximately 9. How many neutrons does a beryllium atom have? 9 5 4 13

answer

5

question

Beryllium, Be, has an atomic number of 4 and an atomic mass of approximately 9. How many electrons does a beryllium atom have? 5 13 9 4

answer

4

question

Fluorine, F, has an atomic number of 9 and an approximate atomic mass of 19. How many electrons does a fluorine atom have? 10 28 9 19

answer

9

question

Two atoms that have the same number of protons but different numbers of neutrons are called... isomers isotopes ions

answer

isotopes

question

What would be the charge of a neon atom that has a full outer shell? -1 +2 no charge +1

answer

no charge

question

Zinc is abbreviated Zn. What is the atomic mass of zinc? 35 95 65.39 30

answer

65.39

question

Gold is abbreviated Au. How many protons does gold have? 79 197 118 276

answer

79

question

An element has 43 protons and 50 neutrons. What is the atomic number of this element? 93 43 50

answer

43

question

Neon has an atomic number of 10 and an atomic mass of approximately 20. How many electrons does neon have in its first shell? 2 10 20 8

answer

2

question

Zinc is abbreviated Zn. How many electrons does zinc have in its first shell? 79 2 197 8

answer

2

question

An element has 43 protons and 50 neutrons. What is the ATOMIC MASS of this element? 43 50 93

answer

93

question

Zinc is abbreviated Zn. How many protons does zinc have? 65.39 35 30 95

answer

30

question

What is the correct molecular formula for caffeine (shown here)? C8H9N4O2 C3H9N4O2 C3H10N4O2 C8H10N4O2

answer

C8H10N4O2

question

A covalent chemical bond is one in which: Electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged Outer shell electrons are shared by two atoms so as to satisfactorily fill the outer electron shells of both. Outer shell electrons of one atom are transferred to the inner electron shells of another atom. Protons or neutrons are shared by two atoms so as to satisfy the requirements of both.

answer

Outer shell electrons are shared by two atoms so as to satisfactorily fill the outer electron shells of both.

question

The lines on the above drawing of caffeine indicate: Covalent bonds Hydrogen bonds Ionic bonds Polar bonds

answer

Covalent bonds

question

Which bond is the weakest? Covalent bonds Hydrogen bonds Ionic bonds All 3 of these bonds are approximately the same strength.

answer

Hydrogen bonds

question

A double covalent bond is the sharing of a total of how many electrons? 2 4 6 8

answer

4

question

A shared pair of electrons is called a: _________. covalent bond hydrogen bond ionic bond polar bond

answer

covalent bond

question

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. This attraction is called: a covalent bond an ionic bond a hydrogen bond

answer

a hydrogen bond

question

What do the four elements most abundant in life - carbon, oxygen, hydrogen and nitrogen - have in common? They are elements produced only in living cells. Each element exists in only one isotopic form. They all have the same number of valence electrons. They all have unpaired electrons in their valence shells.

answer

They all have unpaired electrons in their valence shells.

question

Weak chemical bonds that form BETWEEN polar molecules are Covalent bonds Hydrogen bonds Ionic bonds None of these answers are correct.

answer

Hydrogen bonds

question

What do atoms form when they share electron pairs? molecules isotopes elements

answer

molecules

question

What determines the number of covalent bonds formed by an atom? Orbitals found in the atom Valence shells in the atom Electrons in the outer valence shell of the atom Electrons in each orbital of the atom

answer

Electrons in the outer valence shell of the atom

question

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. This attraction is called: a covalent bond a hydrogen bond an ionic bond

answer

a hydrogen bond

question

What bond(s) is (are) disrupted in the presence of water? atomic ionic molecular covalent

answer

ionic

question

What do the four elements most abundant in life - carbon, oxygen, hydrogen and nitrogen - have in common? They all have the same number of valence electrons. They all have unpaired electrons in their valence shells. They are elements produced only in living cells. Each element exists in only one isotopic form.

answer

They all have unpaired electrons in their valence shells.

question

Table salt is composed of Na+ and Cl- to form NaCl. This type of bond is called: _____________. Polar Ionic Hydrogen Covalent

answer

Ionic

question

Compare the liquid and solid states of water. Which statement is true? Liquid water is more dense Solid water is more dense

answer

Liquid water is more dense

question

Polar molecules are hydrophilic. True False

answer

true

question

Which of the following statements is true concerning hydrogen bonding and the liquid and solid states of water? Only liquid water forms hydrogen bonds. Only solid water forms hydrogen bonds. Both liquid and solid states of water form hydrogen bonds.

answer

Both liquid and solid states of water form hydrogen bonds.

question

Which characteristic of water protects fish when a lake freezes? water is less dense as a solid cohesion water as a solvent All of the these characteristics.

answer

water is less dense as a solid

question

Detergents are neither polar nor nonpolar nonpolar amphipathic polar

answer

amphipathic

question

Which of the following statements is true? Water moves up a tree in tubes. These tubes must be polar. Water moves through a tree mainly using the force of gravity. Non-polar molecules would move up trees in the same way water does. All of these are true

answer

Water moves up a tree in tubes. These tubes must be polar.

question

Which of the following molecules is hydrophilic? butter olive oil table salt

answer

table salt

question

You are able to fill a glass with water so that the water goes above the rim of the glass. What property of water have you observed? moderates temperature density cohesiveness

answer

cohesiveness

question

You make a cup of tea. What is the solute? the tea leaves the tea leaves and water together the water

answer

the tea leaves

question

What is the pH of bleach? very acidic slightly acidic slightly basic very basic

answer

very basic

question

Solution A has a lower concentration of H+ than solution B. Solution A is more acidic more basic more neutral

answer

more basic

question

You test soda (pH 2.5) with blue litmus paper. What color would you expect to see? Yellow Green Red Blue

answer

Red

question

You test bleach (pH 13) with red litmus paper. What color would you expect to see? Blue Yellow Red Green

answer

Blue

question

A small amount of acid is added to a buffered solution. What will happen? The pH will change very little, if at all. The buffer will accept the hydrogen ions from the added acid, keeping pH constant. The pH will increase rapidly after acid is added. The pH will decrease rapidly after acid is added. The pH will change very little, if at all. The buffer will donate extra hydrogen ions to the solution to keep the pH constan

answer

The pH will decrease rapidly after acid is added.

question

Which of the following is the strongest base? baking soda, pH 8.5 stomach acid, pH 1 ammonia, pH 12 black coffee, pH 5 water, pH 7

answer

ammonia, pH 12

question

What is the pH of lemon juice? very acidic slightly acidic slightly basic very basic

answer

very acidic

question

You have a solution that has a pH of 5 and need it to be pH 8. What do you do? Add a base Add water Add an acid

answer

Add a base

question

The pH of a substance is determined by measuring the ____________ of the substance. electrical charge toxicity hydrogen ions chemical reactivity

answer

hydrogen ions

question

A strong base is dripped into a buffered solution. What will happen as a large amount of base is added to the solution? At first, the pH will not respond much. Then, when the buffering capacity is \"used up,\" pH will increase rapidly as more base is added until some limit is reached. At first, the pH will not respond much. Then, when the buffering capacity is \"used up,\" pH will decrease rapidly as more base is added. The pH will start to increase as soon as base is added, and will continue to increase until it reaches 14. The pH will start to decrease as soon as base is added, and will continue to decrease until it reaches 0.

answer

At first, the pH will not respond much. Then, when the buffering capacity is \"used up,\" pH will increase rapidly as more base is added until some limit is reached.

question

Buffers do all of the following EXCEPT: Help organisms maintain homeostasis. Donate (provide) hydrogen ions to the solution when an base is added to the solution. Make a solution strongly acidic Absorb excess hydrogen ions when an acid is added to a solution. Maintain a stable pH within a solution.

answer

Make a solution strongly acidic

question

Solution A has a lower concentration of H+ than solution B. Solution A is more neutral more acidic more basic

answer

more basic

question

The pH of a substance is determined by measuring the ____________ of the substance. chemical reactivity toxicity electrical charge hydrogen ions

answer

hydrogen ions

question

You test soda (pH 2.5) with blue litmus paper. What color would you expect to see? Green Yellow Red Blue

answer

Red

question

A solution with a pH of 4 has how many H+ ions compared to a solution with a pH of 6? 1000 times less 100 times more two thirds as many 1000 times more 100 times less

answer

not 1000 times more or 100 times less

question

You have a solution that has a pH of 5 and need it to be pH 8. What do you do? Add water Add an acid Add a base

answer

Add a base

question

Solution A has a higher concentration of H+ than solution B. Solution A is more acidic more basic more neutral

answer

more acidic

question

pH is a measure of toxicity hydrogen ions chemical reactivity electrical charge

answer

hydrogen ions

question

You have a solution that has a pH of 8 and need it to be pH 5. What do you do? Add a base Add an acid Add water

answer

Add an acid

question

Fluorine, F, has an atomic number of 9 and an approximate atomic mass of 19. How many neutrons does a fluorine atom have? 9 28 10 19

answer

10

question

Neon has an atomic number of 10 and an atomic mass of approximately 20. How many protons does an atom of neon have? 30 5 10 20

answer

10

question

What is the monomer that is used to build proteins? Amino acids Monosaccharides Fatty acids Nucleotides

answer

Amino acids

question

Complete the sentence: All organic molecules contain ____________. carbon oxygen nitrogen all of these are true

answer

carbon

question

Which of these molecules is not organic? Select all that apply. Water Fatty acid Caffeine Silica dioxide: quartz Styrene

answer

Silica dioxide: quartz

question

Which of the following are functions of carbohydrates? Select all that apply. Energy storage Structure Cell recognition Cell signaling None of these choices

answer

Energy storage Structure Cell recognition Cell signaling

question

What do starch and cellulose have in common? Select all that apply. They both have the same linear structure. They both have the same function They are both made of glucose subunits. They are both made by plants.

answer

They are both made of glucose subunits. They both have the same linear structure.

question

Which of the following is the smallest? Ribose Lactose Starch Sucrose

answer

Ribose

question

What type of molecule is shown here? Amino acid Carbohydrate Nucleotide Lipid

answer

Carbohydrate

question

This carbohydrate is produced by animals for energy storage Cellulose Glycogen Chitin Starch

answer

Glycogen

question

Which polysaccharide is most similar to chitin? Glycogen Starch Cellulose Glucose

answer

Cellulose

question

What characteristic of carbon makes it a good backbone for creating diverse and durable molecules? Carbon is a large atom. Carbon forms four covalent bonds. Carbon forms hydrogen bonds. All of these are true.

answer

Carbon forms four covalent bonds

question

Which of the following is characterized as dietary fiber? Sucrose Cellulose Glycogen Starch

answer

Cellulose

question

Which of the following is characteristic of carbohydrates? Carbohydrates are hydrophobic and have the general formula CH2O. Carbohydrates are hydrophilic and have the general formula CH2O. Carbohydrates are hydrophobic and have the general formula CHO. Carbohydrates are hydrophilic and have the general formula CHO.

answer

Carbohydrates are hydrophilic and have the general formula CH2O.

question

What is this structure? cholesterol saturated fatty acid unsaturated fatty acid phospholipid triglyceride

answer

triglyceride

question

What is the name of this structure? unsaturated fatty acid phospholipid cholesterol triglyceride saturated fatty acid

answer

cholesterol

question

Which of the following are functions of steroids? Select all that apply. communication maintain membrane fluidity precursors to vitamins enzymes

answer

communication maintain membrane fluidity

question

How many glycerols in a triglyceride? 1 2 3 4

answer

1

question

What type of lipid is shown here? Steroid Fatty acid Triglyceride Phospholipid

answer

Steroid

question

Which lipid is mainly used for energy storage? phospholipids steroids triglycerides waxes

answer

triglycerides

question

Which characteristic of trans fats has been linked to an increased risk of heart diseases? They increase the levels of both HDL and LDL They increase the levels of LDL They increase the levels of HDL

answer

They increase the levels of LDL

question

Which type of lipoprotein is carried to the liver for processing? LDL HDL Both of these

answer

HDL

question

Which part of the lipid shown is hydrophilic? The red circle The entire phospholipid is hydrophobic The entire phospholipid is hydrophilic The blue lines

answer

The red circle

question

Which molecule makes up the bulk of a cell's membrane? Polysachharides Proteins Phospholipid Monosaccharides

answer

Phospholipid

question

Which lipids have fused carbon rings? Phospholipids Triglycerides Steroids Waxes

answer

Steroids

question

What type of molecule is shown here? Carbohydrate Nucleic Acid Protein Lipid

answer

Lipid

question

Which lipids have 2 long hydrocarbon chains linked by an ester group? Phospholipids Triglycerides Waxes Steroids

answer

Waxes

question

Which lipid provides a water protective layer on the surface of some animals and plants? triglycerides waxes phospholipids steroids

answer

waxes

question

Which molecule makes up the bulk of a cell's membrane? Polysachharides Monosaccharides Proteins Phospholipid

answer

Phospholipid

question

Where do peptide bonds form? Between amino acids of two different protein chains. Between adjacent amino groups on amino acids. Between adjacent carboxyl groups on amino acids. Between the carboxyl group of one amino acid and the amino group of another amino acid.

answer

Between the carboxyl group of one amino acid and the amino group of another amino acid.

question

The amino acid valine is shown with its sidechain atoms highlighted in yellow. Do you think this amino acid is hydrophilic or hydrophobic?

answer

hydrophobic (non-polar)

question

The following shows the dipeptide alanine-serine. Four atoms are labeled. Which atom is part of the peptide bond that joins the two amino acids? Atom A Atom B Atom C Atom D

answer

Atom B between the o and the n right in the middle

question

The sequence and folded form of three different proteins are shown below. Although the sequences are different, the folded structures are the same (S shaped). Which of the following three structures will be the least stable (white=polar sidechains, black=non-polar sidechains). protein A protein B protein C

answer

protein C wwwwbwbbwwww

question

Which of the following diagrams represents the correct structure of a protein? Each blue-gray-red box represents an amino acid.

answer

a bgr bgr bgr bgr bgr bgr * * *

question

Which of the following changes when a protein denatures? Length of the entire protein Amino acid sequence Three dimensional structure

answer

Three dimensional structure

question

Which of the following four proteins would bind best to the antibody? The portion of the antibody the binds the protein is shown on the left, the proteins (A, B, C, D) on the right. Protein A Protein B Protein C Protein D

answer

c :same as diagram

question

Where do competitive inhibitors bind on an enzyme? substrate allosteric site competitive site active site

answer

active site

question

A ligand cannot bind to the active site of an enzyme. True False

answer

False

question

Two enzymes catalyze the same reaction. Enzyme A converts substrate to product twice as fast as enzyme B. Which enzyme has the lower activation energy or energy barrier: A or B? Enzyme A Enzyme B

answer

Enzyme A

question

Amino acids in a protein chain are attached by bonds called

answer

peptide bonds

question

This amino acid is ______________. hydrophobic hydrophilic

answer

hydrophilic

question

The peptide bond that forms between two amino acids is an example of a(n): hydrogen bond ionic bond covalent bond

answer

covalent bond

question

Which of the following curves best represents the activity of an enzyme isolated from a bacteria that lives in the hot springs in Yellowstone (water temperature 120 degrees C)? curve A curve B curve C

answer

curve B curves up then down and goes past 120

question

Which of the following plots more correctly shows the activity of pepsin as a function of pH? plot A plot B plot C plot D

answer

plot A goes up then down like a volcano starts at 0

question

An enzyme binds the indicated substrate and converts it to product by removing two hydrogen atoms and forming a double bond between the two middle carbons. Compounds A and B are inhibitors of this enzyme. Which of the two inhibitors is a non-competitive inhibitor? Compound A Compound B

answer

Compound B

question

This is an image of Deoxyribose pyrimidines Ribose pyrimidine Ribose purine Deoxyribose purine

answer

Deoxyribose pyrimidines

question

Which nucleotide is at the 3' end of this nucleic acid? G A T C

answer

t

question

Does the DNA in the skin cell have the same backbone as DNA in the brain cell of the same organism? Yes, all backbones of ALL DNA molecules are the same. Yes, the backbones of DNA are different for each person, but within the organism - they are the same in all cells. No, the backbones will be different in each cell type. No, the backbones will be different because of mutations.

answer

Yes, all backbones of ALL DNA molecules are the same.

question

Which labeled region is the base? Blue Green Red

answer

Green

question

How many phosphate groups does ATP have? 1 2 3 4

answer

3

question

Which of these is NOT a difference between DNA and RNA? DNA tends to be double stranded, while RNA tends to be single stranded RNA uses the base thymine while DNA uses the base uracil. DNA uses the sugar deoxyribose while RNA uses the sugar ribose. All of these are differences between DNA and RNA.

answer

RNA uses the base thymine while DNA uses the base uracil.

question

The molecule shown here is: _________________ an amino acid a carbohydrate a nucleotide a lipid

answer

an amino acid

question

The cells of your body are surrounded by water. The outer layer of these cells is made of many nonpolar molecules. What would happen if the outer layer of these cells was made of mainly polar molecules? The cells would dissolve. The cells could not interact with their environment. The cells would be too heavy to float in the water. Water could not get in to the cell.

answer

The cells would dissolve.

question

Which of the following is used for long term energy storage? Proteins Nucleic Acids Carbohydrates Lipids

answer

Lipids

question

What type of molecule is shown here: Carbohydrate Lipid Nucleotide Amino acid

answer

Lipid

question

Which of these functional groups is hydrophilic? Alcohols Carboxyl Phosphate All of the other selections.

answer

All of the other selections.

question

This is an image of Deoxyribose purine Deoxyribose pyrimidines Ribose purine Ribose pyrimidine

answer

Deoxyribose purine

question

Enzymes are usually ______________? carbohydrates nucleotides lipids proteins

answer

proteins

question

Detergents are ______________. polar nonpolar both polar and nonpolar neither polar nor nonpolar

answer

both polar and nonpolar

question

How will lipids respond when immersed in water? The phospholipids will form crystals at the bottom of the solution The phospholipid will dissolve evenly in the water The heads will orient away from the water The tails will orient away from the water

answer

The tails will orient away from the water

question

Proteins begin with an amino group and end with a carboxyl group. In the case of nucleic acids: They begin at the 3' end and end at the 5' end. They begin at the 5' end and end at the 3'. It is the same in nucleic acids. They begin at the 5' end and end at the 2' end

answer

They begin at the 5' end and end at the 3'.

question

Which of the following is mostly hydrophobic? Carbohydrates Proteins Nucleic acids Lipids

answer

Lipids

question

Which is NOT a function of proteins? Maintains structure of animal cells Move substances in and out of the cell. Form the bulk of cellular membranes. Recognition of specific particles.

answer

Form the bulk of cellular membranes.

question

Which of the following structures can be found together in eukaryotic cells? DNA and ribosomes ribosomes and endoplasmic reticulum cytoplasm and ribosomes cytoplasm and plasma membrane

answer

ribosomes and endoplasmic reticulum

question

Which of the following statements about prokaryotes is incorrect?

answer

Prokaryotes have circular pieces of DNA within their nuclei.

question

A forensic examination reveals cells containing ribosomes, DNA, a plasma membrane, and a cell wall. What type of cell it is?

answer

bacterium

question

Which is NOT a difference between prokaryotic and eukaryotic cells?

answer

Eukaryotes are larger than prokaryotes.

question

Which of these is also called an antibiotic in a medical setting?

answer

Antibacterial

question

Which is a plausible effect of taking oral antibiotics?

answer

The antibiotics could unintentionally kill good bacteria living in your intestines, leaving you more susceptible to infection by pathogenic bacteria.

question

What is the concern with overuse of antibiotics?

answer

Bacteria will become antibiotic resistant.

question

All living things are made of one or more cells: true or false?

answer

True

question

All cells have ______________?

answer

plasma membrane

question

An ideal antibiotic damages only bacterial cells but not human cells. Which of the following cellular structures would be a good target for antibiotics?

answer

cell wall

question

How does the selective permeability of the membrane help the cell.

answer

This allows the cell to regulate what enters and exits

question

Which substance would be most likely to pass through a lipid bilayer/plasma membrane without embedded proteins?

answer

a steroid hormone

question

Biological Membranes are:

answer

dynamic.

question

Which component of the plasma membrane has the widest variety of functions?

answer

proteins

question

What is the role of carbohydrates in the plasma membrane?

answer

cellular identification

question

A set of erythrocytes is placed in a beaker of 0.9% NaCl. Nothing appears to happen to the cells. Why?

answer

0.9% NaCl is iostonic to the cells.

question

All of the following have an effect on the fluidity of a membrane except:

answer

the presence of integral proteins in the membrane

question

Which of the following can cross the cell's plasma membrane without the assistance of protein transporters? Select all that apply.

answer

small hydrophobic molecules gasses

question

An animal cell placed in a hypotonic solution will __________.

answer

burst

question

A substance, such as glucose, will enter a cell following its concentration gradient, from the blood and tissues, through the membrane, and into the cytoplasm. Such movement of glucose has a maximal capacity, does not require energy, and is specific only for glucose. How is the entry of glucose into the cell occurring?

answer

By facilitated diffusion

question

The secretion of materials, such as hormones and neurotransmitters, from inside of a cell to the outside is ___________.

answer

exocytosis

question

An immune cell would engulf a pathogenic cell using the process of: ________________ ?

answer

endocytosis

question

A substance, such as glucose, will enter a cell following its concentration gradient, from the blood and tissues, through the membrane, and into the cytoplasm. Such movement of glucose has a maximal capacity, does not require energy, and is specific only for glucose. How is the entry of glucose into the cell occurring?

answer

By facilitated diffusion

question

Increasing the concentration gradient:

answer

Increases the rate of diffusion

question

Sodium ions are more highly concentrated outside the cell, in the extracellular fluid. Which process would be used to return any sodium ions that leaked into the cell back to the extracellular fluid?

answer

active transport

question

Protein transporters that move materials against a concentration gradient are active transport proteins.

answer

True

question

Active transport could also be called facilitated diffusion.

answer

False

question

A cell will uptake large molecules from the extracellular fluid by the process of __________.

answer

endocytosis

UMUC Biology 103

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