Biology Test #1

The atomic number of an element is equal to the number of:

protons only

Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent?

quaternary

A cytologist is examining a tissue under an electron microscope. He notices that the endoplasmic reticulum of each cell is extremely rough in appearance and he knows that the rough appearance is because of the ribosomes embedded there. He asks why there are so many ribosomes. You respond,

"This tissue exports proteins to other areas of the body."

An atom has 20 electrons and 20 neutrons. What is the mass of this atom?

40

A chemist adds a chemical to pure water and there is a 100 fold increase in the concentration of hydrogen ions. What is the best approximation of the new pH value?

5

There are many similarities between DNA and RNA. What statements support this idea? Check all that apply.

- Both DNA and RNA nucleotides contain the nitrogenous bases adenine, cytosine, and guanine. - Both DNA and RNA contain monosaccharide sugars on their respective nucleotides. - Both DNA and RNA are involved in the "Central Dogma" of biology. - Both DNA and RNA contain phosphate groups on their respective nucleotides

Complete the sentences using the words provided, acids and bases.

-A(n) (acid) acts to increase the hydrogen ion concentration of a solution. -A(n) (base) acts to decrease the hydrogen ion concentration of a solution. -A(n) (buffer) acts to maintain a relatively stable concentration of hydrogen ions in a solution. -As the hydrogen ion concentration of a solution decreases, the pH (increases). -As the pH of a solution increases, the concentration of (hydroxide) ions increases. -The pH of a solution is defined as the (negative logarithm) of the hydrogen ion concentration. -As the hydrogen ion concentration of a solution increases, the pH (decreases).

Complete the sentences using the words provided.

-All carbohydrates are composed of one or more (monosaccharides) -A protein is composed of one or more long, unbranched chains called (polypeptides) which are coiled and folded into a specific 3-dimensional shape. -A polypeptide is composed of monomers called (amino acids). -Nucleic acids are composed of monomers called (nucleotides). -Triglycerides are composed of glycerol and (fatty acids). -Glucose, starch, and cellulose are all examples of (carbohydrates). -RNA and DNA are examples of (nucleic acids). -Fats, steroids, and terpenes are examples of (lipids). -Polymers are formed by linking monomers together through (condensation) reactions. -Breaking the bonds between the subunits of a polymer involves (hydrolysis) reactions. -During a hydrolysis reaction, a molecule of water is (broken down). -During a condensation reaction, a molecule of water is (formed).

The cell theory includes different tenets to explain the organization of life. What principles comprise the cell theory? Check all that apply

-All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells. All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells. -Cells are the smallest living things, the basic units of organization of all organisms. -Cells arise only by division of a previously existing cell.

The pH for several solutions is given below. After filling in each blank with the correct number, arrange the solutions in order from most acidic to most alkaline.

-Beer has a pH of 3, therefore its H+ concentration is 100times greater than a solution with a pH of 5. -Black coffee has a pH of 5, therefore its H+ concentration is 100,000 times greater than a solution with a pH of 10. -Urine has a pH of 6, therefore its H+ concentration is 1,000 times greater than a solution with a pH of 9. -Household ammonia has a pH of 11, therefore its H+ concentration is 10,000 times less than a solution with a pH of 7.

Water interacts with polar substances like -OH groups but not with non-polar substances like methyl (-CH3) or ethyl groups (-CH2). Using this information, select the molecules that will easily dissolve in water based on polarity not on size. Check all that apply.

-CH3OH -CH3 CH2 CH2 OH

What facts would you select to show the major significance of the element carbon in the human body? Check all that apply.

-Carbon has four valance electrons. -Carbon forms the backbone of all organic molecules. -Carbon can form bonds with four different atoms. -Carbon-containing molecules can form rings, branches, or coils.

Identify which molecule is DNA and which is RNA, and then label the parts of each molecule.

-DNA- deoxyribose-phosphate backbone, purine bases, and hydrogen bonds between base pairs. -RNA- ribose-phosphate backbone, and pyrimidine bases.

All cells exhibit basic structural similarities. The general plan of cellular organization varies between different organisms, but despite these modifications, all cells resemble one another in certain fundamental ways. Match each description with a feature.

-Nucleus- contains eukaryotic DNA -Nucleoid- contains prokaryotic DNA -Plasma Membrane- separates contents of cell from surroundings, made up of phospholipid bilayer. -Cytoplasm- semifluid matrix, contains sugars salts and amino acids.

Complete the sentences using the words provided, components of elements.

-The atomic number of carbon-13 is (six). -The atomic mass of carbon-13 is (thirteen). -If different atoms have the same number of protons but different numbers of neutrons they are called (isotopes). -Substances composed of atoms that all have the same number of protons are called (elements). -Atoms that have gained or lost electrons and are no longer electrically neutral are called (ions). -The nucleus of an atom always contains one or more (protons). -The orbitals of an atom contain negatively charged particles called (electrons).

Complete the sentences with the words provided. Then arrange the sentences so the levels of organization go from smallest to largest.

-The level of organization that is more complex than an atom but less complex than an organelle is a(n) (molecule). -Molecules may be assembled into a microscopic structure called a(n) (organelle) which carries out specific functions within a cell. -The simplest level of organization that can carry out all of the functions of life is a(n) (cell). -A (tissue) is a group of similar cells that act as a functional unit. -Your brain is an example of a(n) (organ). -A group of organisms that belong to the same species and live in the same place is called a(n) (population). -A biological community together with its physical habitat constitutes a(n) (ecosystem).

The DNA sequence capable of pairing with 5' CGATTAGT 3' is:

3' GCTAATCA 5'.

Complete the sentences using the words provided, simple sugars.

-This diagram illustrates a (dehydration) reaction. -Glucose is a (monosaccharide). -Sucrose is a (disaccharide). -The molecule in this diagram that is commonly used as a transport sugar in plants is (sucrose). -The molecule in this diagram that is commonly used as a transport sugar in humans is (glucose). -The glucose molecule in this diagram is shown in the (ring) form. -Fructose has (six) carbon atoms.

Place these statements into the proper categories, Synthesis and degrading molecules.

-dehydration synthesis 1) a molecule of glycogen is formed by linking glucose molecules thru this process. 2)this process removes water to link 2 or more amino acids. 3)monomers are linked together thru this process. -denaturation 1)the change to the color and consistency of an egg during cooking is an example of this process. 2)using acids to cook raw fish is an example of this process. 3)this process does not involve breaking peptide ponds but it does involve unfolding protein structure. -hydrolysis 1)breaking DNA into nucleotides involves this process 2)the addition of water to break proteins into amino acids is an example of this process. 3)the separation of polymers into smaller units makes use of this process.

Match each name with the appropriate structure in the diagram, endomembrane system.

-lumen- an interior space -rough ER- functions in the synthesis and modification of proteins. -transport versicle- transports newly synthesized proteins. -smooth Er- functions in the synthesis of carbs and lipids. -cis face- receives vesicles. -golgi apparatus- functions in the collection, packaging, and distribution of molecules. -trans face- distributes vesicles. -secretory vesicle- carries proteins to be released from the cell.

Match each label with the correct structure in the figure, structure of mitochondria.

-outer membrane -inner membrane -inter-membrane space- space between both membranes. -crista- the fold in the membrane. -dna- contains genes that encode proteins. -ribosomes- site of protein synthesis. -matrix- space inside the mitochondria.

Match each label with the correct structure in the figure, structure of chloroplasts.

-stroma- fluid matrix inside the chloroplasts -granum- the stack of thylakoids -inner membrane -outer membrane -thylakoid membrane- contains photosynthetic pigments -ribosome- site of protein synthesis -DNA- contains genes that encode proteins

Identify the 3 parts of a nucleotide.

-sugar -phosphate group -nitrogenous base

Indicate whether each of the following statements about atomic structure is true or false

1. A neutral oxygen atom (atomic number = 8) has 8 electrons located in 2 different electron orbitals. False 2. Hydrogen has only one neutron and no protons in its nucleus. False 3. An atom consists of a central nucleus surrounded by electrons that are in constant motion. True 4. Almost all of the mass of an atom is concentrated in its electrons. False 5. The orbital of an electron is the volume of space where the electron is most likely to be found. True 6. Almost all of the volume of an atom is empty space. True 7. The reactivity or chemical behavior of an atom depends primarily on the number of neutrons it has. False 8. Modern physics indicates that we cannot determine the exact location of a particular electron at any given time. True 9. Electrons are maintained in their orbitals by their attraction to the positively charged nucleus. True 10. Atomic orbitals represent probability distributions for electrons and come in a variety of shapes. True

Match the following molecules with their function, nucleotide function.

1. DNA Contain genes that can be transcribed 2. mRNA Translated into proteins 3. ATP Provide energy for cell activities 4. NAD+ and FAD Transport electrons

Match the organelle with its function

1. Nucleus -Contains instructions for protein synthesis and cell reproduction; contains genetic information. 2. Endoplasmic reticulum-Intracellular compartment forms transport vesicles; participates in lipid synthesis and synthesis of membrane or secreted proteins. 3. Golgi apparatus- Packages proteins for export from cell; forms secretory vesicle. 4. Lysosomes-Digest worn-out organelles and cell debris; digest material taken up by endocytosis. 5. Vacuole- Carries out a variety of functions including regulating water levels in plant cells. 6. Peroxisome- Involved in the breakdown of fats and contains the enzyme catalase.

Characteristics of life

1. The roots of a plant grow toward a source of water. Sensitivity 2. The body temperature of a dog is more stable than the temperature of its environment. Homeostasis 3. A cat is composed of organ systems, which are composed of organs, which are composed of tissues, which are composed of cells. Ordered complexity 4. A bacterial cell divides to form two new cells. Reproduction 5. In order to carry out essential life functions such as growth, development, and movement, a duck must eat. Energy utilization 6. In 1980, scientists determined that 2% of the honey bees in Texas had a gene that makes them more aggressive. By 2005, the frequency of this gene in the Texas honeybee population had increased to 15%. Evolution

Carbohydrates are used in cells for structural purposes and as an energy source. What is the main type of carbohydrate contained in each of the following? 1. Potato as food 2. Fruit as food 3. Stored human energy 4. Human blood sugar.

1. starch 2. fructose 3. glycogen 4. glucose

A DNA molecule containing 32% thymine would contain how much cytosine?

18%

As ATP moves from the matrix of the mitochondrion to the cytoplasm of a cell, how many membranes will it pass?

2

A double stranded DNA strand contains 26 pyrimidines. How many purines will the copied strand contain?

26

A DNA molecule with 24% guanine would have how much adenine?

26%

How many water molecules would be produced from the dehydration reactions associated with making a protein that has a primary structure consisting of 293 amino acids and that has a quaternary structure consisting of 2 identical subunits?

584

Oxygen has an atomic mass of 16 and an atomic number of 8. How many neutrons are present?

8

Which of the following reactions is a dehydration reaction?

A + B → C + H2O

Which of the following reactions is a hydrolysis reaction?

A + H2O → B + C

Carbohydrates are polymers formed of structural units called:

monosaccharides

The specific amino acid sequence of a protein is its ____.

primary structure

DNA and RNA contain functional units known as:

nucleotides

A circular molecule of DNA devoid of any histone proteins describes the chromosome of a (an):

bacteria

You have identified an enzyme that appears to be involved in the addition of palmityl group (a fatty acid) to certain proteins. Knowing that palmitoylated proteins are usually targeted for delivery to the plasma membrane, in which organelles might this enzyme be expressed?

Golgi apparatus and endoplasmic reticulum

Ribosomes are made up of:

protein and RNA.

A distinctive feature of eukaryotes is the organization of tightly packaged chromosomal DNA with proteins into a membrane-bound structure called a:

nucleus

During which cellular process do all three forms of RNA associate?

protein synthesis

What functional groups are present on this molecule? Check all that apply, functional groups.

Carboxyl, Hydroxyl, amino.

The cytoplasmic space in eukaryotic cells is occupied by many diverse membrane-bound structures with specific cellular functions called:

organelles

What common life characteristic would cells from a daisy, bacteria, and a dog all have?

DNA

Macromolecules that are used by all organisms to store hereditary information are called:

DNA molecules.

According to most car mechanics, plain water is the best coolant to use in an engine provided the engine is not being exposed to freezing temperatures. If the car is subject to freezing temperatures then a mixture of water and ethylene glycol (antifreeze) is recommended but it does not cool as efficiently as plain water. Why would ethylene glycol reduce the cooling efficiency of water?

Ethylene glycol has a lower heat capacity than water.

Prokaryotic cells are smaller than eukaryotic cells. What is a plausible explanation?

Eukaryotes have compartmentalization, which allows for specialization.

Oxygen-16 is abundant and has 8 protons and 8 neutrons. Oxygen-18 has two extra neutrons. These two forms are:

oxygen isotopes.

Proteins are created with:

peptide bonds

Yogurt contains galactose and glucose, which are generated when bacterial enzymes act on milk sugars. What is the main source of the galactose in yogurt?

Lactose

What is the difference between mitochondria and chloroplasts?

Mitochondria are oxidative metabolic bacteria derivatives and chloroplasts are photosynthetic bacteria derivatives.

This is a nucleotide containing molecule that is commonly used to carry electrons in the cell.

NAD+

Biological membranes contain bilayers containing mostly ______.

phospholipids

Based on the function of mitochondria, what substance is able to pass through the outer membrane of the mitochondria easily?

Oxygen

Tay-Sachs disease causes lysosomes to rupture. How would this affect the cell? Check all that apply.

Phagocytic cells would not destroy bacteria. Phagocytic cells would not destroy bacteria. Material taken up through endocytosis would not be digested. Material taken up through endocytosis would not be digested. Biological polymers would not be broken down by lysosomes.

You label cells with a radioactive isotope of sulfur (35S). The only molecules that would be radioactively labeled in these cells are:

Proteins

A cell biologist has developed a new drug that blocks vesicle transport at the cis face of the Golgi apparatus. What will this drug prevent from happening inside a cell?

The movement of the lipids and proteins from the endoplasmic reticulum to the Golgi apparatus.

If water were non-polar it would not form hydrogen bonds. At normal room temperatures this non-polar water would be _____.

a gas

Water boils at a higher temperature than a non-polar solvent like ether because...

a large amount of energy is required to break the many hydrogen bonds that restrict the movement of individual water molecules.

Phospholipids are made up of:

a phosphate, two fatty acids and a glycerol.

Schleiden and Schwann stated the "cell theory," which in its modern form says:

all organisms are composed of one or more cells, all cells are the smallest living things and all cells arise by division of other cells.

Relatively small organic molecules with a central carbon atom which is bonded to a carboxyl group, an amino group, a carbon containing group, and a hydrogen atom are called:

amino acids

The peptidoglycan of bacterial cell walls contains a carbohydrate matrix linked together by short chains of:

amino acids

You explain to your study group that a hypothesis is:

an explanation that accounts for careful observations.

A bobcat is feeding on a white-tailed deer. It first eats the liver, which is rich in stored sugars. In what form would sugar be stored in the deer's liver?

glycogen

A team of researchers is studying the external structures on the dorsal (back) surface of a spider mite. The spider mite seems to be the habitat of an even smaller mite, which is approximately 0.05mm. While they can see the dorsal surface of the spider mite with their naked eye, they cannot see the mite clearly. The researchers are writing a grant to provide support for a microscope to use to study these new mites. They need to purchase a microscope with a high magnification to observe the new mites on their habitat. Based on the information given, what type of microscope would you suggest?

binocular compound light microscope

This atom in its unbound state has four valence electrons. These electrons readily form single, double, and even triple bonds among themselves to become stable. This atom is:

carbon

Plants, fungi and bacterial all have:

cell walls

When looking at plant and animal cells with an electron microscope, you notice that the plant cells have more Golgi membranes than the animal cells. This is most likely because unlike in animal cells, in plant cells the Golgi apparatus is involved in the production of:

cell walls

Humans are unable to get metabolic energy from cellulose because:

cellulose digesting enzymes are absent from the human gut.

Plant cells often have a large membrane-bound sac that is used for storing water and other substances called a:

central vacuole

A polysaccharide that is composed of modified glucose subunits and that is found in the exoskeletons of insects and crustaceans is known as:

chitin

The distinctive feature of chloroplasts is that they contain a green pigment called:

chlorophyll.

Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable termed a(n) _____.

control

When two atoms share a pair of electrons, the bonding is referred to as:

covalent.

The spreading of cancer cells, wound healing, and blood clotting all rely on the same type of cell movement called:

crawling

The semi-fluid matrix that surrounds organelles in a cell is called the:

cytoplasm

Mitochondrial disorders can be caused by mutations in all the following except:

cytoplasmic DNA

Your microwave will not turn on, and you speculate that a circuit breaker in the house has been tripped. In scientific terminology, the steps would be described as:

developing a hypothesis based on an observation.

In eukaryotes, mitochondria are the organelles primarily involved in:

energy release/capture.

Organic molecules have a carbon backbone and _____ such as -OH and -NH2 that affect their chemical properties.

functional groups

A monosaccharide that plays an important role in energy storage is a six-carbon sugar called:

glucose

Water molecules are polar with ends that exhibit partial positive and negative charges. These opposite charges allow water molecules to attract each other through:

hydrogen bonds

Macromolecules are broken down to monomers in ___

hydrolysis reactions.

Dr. Ratard was trying to determine the cause of a mysterious epidemic affecting fish in the gulf of New Mexico. His proposal that the deaths were caused by an organism called a protist is considered a(n) _________

hypothesis

A yellow jacket, an insect in the order Hymenoptera, stung me. A wasp, an insect in Hymenoptera, stung me. A hornet, an insect in Hymenoptera, stung me. I see a pattern. All insects in this order must have stingers. What type of reasoning does this represent?

inductive reasoning

Inductive/deductive reasoning

inductive- data deductive- definition

In the crystal matrix of ordinary salt, the sodium and chlorine are held together by:

ionic bonds.

When atoms gain or lose electrons, they become negatively or positively charged. These negatively or positively charged atoms are known as

ions

Carbon-12, Carbon-13 and Carbon-14 are examples of:

isotopes

Peroxisomes are examples of:

microbodies

The organelle involved in the oxygen-requiring process by which the energy harvested from macromolecules is used to generate ATP is the:

mitochondria

Fructose and galactose both have six carbon atoms, twelve hydrogen atoms and six oxygen atoms, just like glucose. A friend of yours says: "Since those sugars have the same number of atoms, they should have the same name." You answer: "While they do have the same number and type of atoms,

they are named differently because they are alternate forms of the monosaccharide, glucose."

Fats are excellent energy storage molecules because:

they have a relatively high ratio of energy storing C—H bonds.

A nucleic acid contains uracil, allowing you to conclude that:

this nucleic acid is RNA.

Three fatty acids bonded together with a glycerol are found in a(n):

triglyceride

Common lipids for energy storage are:

triglycerides