GVSU Bio 120 Exam 1 (Chapter 1-5)

Which of the following is not one of Charles Darwin's observations?

A population avoids competition by producing only as many offspring as can successfully reproduce on their own

What is the difference between covalent bonds and ionic bonds?

Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms.

Which of the following are compounds?

H2O and CH4, but not O2

How many valence electrons do the most common elements of living things have (e.g., oxygen, carbon, etc.)?

H: 1, O: 6, N: 5, C: 4

What is a "halocline"?

Halocline: a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water. Because salinity affects the density of seawater, it can play a role in its vertical stratification. It is made of the things that fall into the blue hole, like human dandruff.

Be able to recognize and discuss specific examples of proteins such as hemoglobin, ovalbumin, and collagen.

Hemoglobin: 4 polypeptide units, 2 alpha and 2 beta, transport protein Collagen: structural (function), fibrous (shape), 4th order polypeptide Ovalbumin: globular (shape), storage (function)

Which of the following statements best describes the chemical conditions just below the halocline in a "blue hole"?

High salinity and low dissolved oxygen

What types of particles are hydrophilic and which are hydrophobic?

Hydrophilic: Molecules that have an attraction to water, charged ions and polar molecules, do dissolve in water Hydrophobic: particles scared of water/ do not react with water, non polar solute, does not dissolve

Which side chains make amino acids hydrophilic or hydrophobic?

Hydrophilic: charged, polar Hydrophobic: non-polar (methyl group)

Be able to name and describe the properties (polar/non-polar, etc) of each of the functional groups we discussed in class.

Hydroxyl: OH, polar, hydrophilic Carbonyl: C=O (carbon double bonded to oxygen), polar, hydrophilic Carboxyl: COOH, polar, hydrophilic Amino: NH2, polar, hydrophilic Sulfhydryl: SH, polar, hydrophilic Phosphate: OPO3^2-, charged, hydrophilic Methyl: CH3, non-polar, hydrophobic

Which of the following statements best distinguishes hypotheses from theories in science?

Hypotheses usually are relatively narrow in scope; theories have broad explanatory power

Which of the following best describes the logic of scientific inquiry?

If my hypothesis is correct, I can expect certain test results.

What is a nucleotide?

The monomers that make up nucleic acids A phosphate, a sugar, and a nitrogenous base 3 and 5 prime ends all look the same, the difference is in the functional groups attached

About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?

carbon, hydrogen, nitrogen, oxygen

Which two functional groups are always found in amino acids?

carboxyl and amino group

Cells are _____.

characteristic of prokaryotic and eukaryotic organisms

Which bond or interaction would be difficult to disrupt when compounds are put into water?

covalent bonds between carbon atoms

How would acidification of seawater affect marine organisms? Acidification of seawater would _____.

decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals

A covalent bond is likely to be polar when ________.

one of the atoms sharing electrons is more electronegative than the other atom

A covalent chemical bond is one in which _____.

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

Be able to describe the concept of pH. What does it mean to be acidic or basic?

pH: measures of hydrogen ion concentration, pH goes up=basic, pH goes down=acid pH scale: each increase or decrease is by 10xnumber of jumps to another number (3 is 1000 times more acidic than 6 because it's 3 jumps) acid: anything that gives up protons when it's put into water, increases hydrogen ion concentration base: anything that gives up hydroxide (--OH-) when it's put into water

Bonds between two atoms that are equally electronegative are _____.

nonpolar covalent bonds

Hydrophobic substances such as vegetable oil are _____.

nonpolar substances that repel water molecules

The relation between amino acid and polypeptide is similar to the relation between ________.

nucleotide and nucleic acid

Carbon-14 has the same ________.

number of protons but more neutrons than carbon-12

How do chemical conditions in a blue hole differ above and below the halocline?

*see notes for specific measures below and above*

A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4?

100 times more

Be able to describe what is meant by "Acidification" (see figure 3.11).

Acidification: to become an acid, adds hydrogen ions to a solution and removes hydroxide ions because of the tendency for H+ to combine with OH-, forming water. pH decreases as hydrogen ions increase.

Why did one electrode make the solution more basic while the other electrode made the solution more acidic? That is, what chemical reaction happened at each electrode?

At the electrode where more bubbles are being made, H is coming off. H2O receiving electrons causes chemical reaction: Hydrogen and hydrogels At the electrode with less bubbles, electrons are being removed, creating Oxygen gas, Hydrogen, and electrons. Since the product is hydrogen the pH goes down making the solution more acidic

What types of organisms live in Bahamas blue holes? More importantly, WHY do they live there?

Bacteria live at the halocline, the things that fall into the blue hole float down to bacteria and they break it down. They get their energy not from the sun but from SO (sulfate) and turn it into H2S (hydrogen sulfate)

Which of the following order is correct in terms of the hierarchy of the organization?

Biosphere → Ecosystem →Community → Population → Organism

What are the levels of biological organization?

Biosphere: all life on Earth and where they exist Ecosystems: All the living things in a particular area (animals, soil, light) Communities: Array of organisms inhabiting an ecosystem Population: All the individuals of a species living within a specified area Organisms: Individual living things (each plant, animal, fungus, bacterium) Organs: A body part that is made up of tissues and has specific functions Tissues: A group of cells that work together to perform a specific function Cells: Life's fundamental unit of structure and function Organelles: Various functional components in cells Molecules: A chemical structure consisting of 2 or more atoms

Be familiar with figure 3.12 on the fate of CO2 in the ocean. What is a buffer?

Buffer: A substance that minimizes changes in the concentrations of H+ ions and OH- in a solution, allows biological fluids to maintain constant pH 1. some carbon dioxide in the atmosphere dissolves in the ocean where it reacts with water to form carbonic acid 2. carbonic acid dissociates into H+ + bicarbonate 3. The added H+ combines with carbonate ions (CO3^2-) forming more bicarbonate 4. less carbonate is available for calcification necessary for the formation of calcium carbonate for marine life

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14?

C-C=C-C

Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton?

C2H4

What elements make up each type of macromolecule?

Carbohydrates and lipids are made of only carbon, hydrogen, and oxygen (CHO) Proteins are made of carbon, hydrogen, oxygen, and nitrogen (CHON) Nucleic acids such as DNA and RNA contain carbon, hydrogen, oxygen, nitrogen, and phosphorus

What are the sub-units of each type of macromolecule (e.g., proteins are made of amino acids)?

Carbohydrates: -monomers: monosaccharides -dimers: disaccharides -polymers: polysaccharides Proteins: -monomers: amino acids/peptides -dimers: dipeptide -polymers: polypeptides Nucleic Acids- DNA and RNA -monomers: nucleotides -dimers: dinucleotides -polymers: polynucleotides Lipids -all hydrophobic molecules (ex. steroids, fats, phospholipids)

What chemical and physical characteristics define each type of molecule (e.g., lipids are hydrophobic)?

Carbohydrates: hydrophilic Proteins: depends on R groups on how it coils Nucleic Acids: DNA and RNA are hydrophilic Lipids: hydrophobic

How many bonds can carbon make? Why?

Carbon can make 4 bonds because it has 4 valence electrons, it can make a variety of different shapes and thus have a variety of functions

The different chemical bonds and weak interactions

Chemical bonds: Attractions between atoms where electrons are either shared or given from one atom to another Ionic: electrons taken from one atom and given to another atom, now both are charged, positive and negative charge of 2 atoms hold bond together Covalent: sharing valence electrons (between 2 nonmetals) Hydrogen Bonds: results from the attraction between the partial positive charge on the hydrogen atom of water and the partial negative charge on ammonia Van der Waal's attraction: sticky feet of lizards

What are the two types of nucleic acids and what are their functions?

DNA: contains deoxyribose as its sugar, functions in storing info and passes it along from generation to generation RNA: contains ribose as its sugar, transmits info from DNA to cellular machinery that makes proteins DNA --> RNA --> proteins --> traits

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.

What does it mean to be denatured? What might cause a protein to denature?

Denaturation: loss of shape/function physical and chemical conditions change due to: pH, temperature, salt concentration, heavy metals, and solvents

Be able to define and use the words used in the "electrolysis of water" demo.

Electrolysis of Water: as electrons flow through , bubbles are given off, the color shows the pH oxidation: loss of electrons reduction: gain of electrons

What is the difference between an element and a compound?

Element: a substance that can't be broken down into other elements through a chemical reaction - a type of matter made of the same atoms Compound: A substance consisting of 2 or more different elements combined into a fixed ratio

Enzymes are a really important class of proteins... how do they function? Be able to use terms like substrate, product, and catalyst.

Enzymes have an active site where the substrate can bind, the substrate binds to the active site, bond of substrate is broken by hydrolysis: splitting bond by adding water, the products are separate sugars that are what make up the substrate

What are examples of different functions proteins may have (e.g., transport, storage, etc.)?

Enzymes: a biological catalyst, breaks down substrates Storage: function in storage of materials Transport: move stuff Hormonal: helps regulate blood sugar Contractile+Motor: movement of cilia and flagelia Structural: support, provide fibrous framework

What is the relationship between natural selection and evolution?

Evolution occurs as the unequal reproductive success of individuals ultimately leads to the adaptation to their environment, as long as the environment stays the same Natural selection is evolutionary adaptation

What does it mean for a protein to be globular or fibrous?

Fibrous: composed of narrow and long strands and have structural role -- are something Globular: more compact and rounded shape and have functional roles -- do something

Which of the following correctly describes chemical equilibrium?

Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products.

What are isomers?

Isomers: different versions/structures of the same molecules -Structural: same molecules, different arrangements of atoms -cis: functional groups on same side -trans: functional groups on different sides -Enantiomers: bonds that are mirror images of each other

Which of the following is true of natural selection?

It requires genetic variation, results in descent with modification, and involves differential reproductive success.

Why is it important that the pH scale is logarithmic?

Logarithmic because it makes the pH scale so compact, represents a wide range of ion activities; when the pH of a solution changes slightly, the actual concentrations of H+ and OH- in the solution change a lot

How does the number of bonds affect the shapes of molecules that carbon and the other elements form?

Structure determine function

What are the most common elements that comprise living things?

Oxygen (65%), Carbon (18.5%), Hydrogen (9.5%), Nitrogen (3.3%), Phosphorous (1%), Sulfur (0.3%)

What does it mean for a molecule to be "polar", or to have "polar covalent bonds"?

Polar: A molecule (such as water) with an uneven distribution of charges in different regions of the molecule, asymmetrical, share electrons unequally Non-polar: Form between two atoms that share their electrons equally Polar covalent bonds: a covalent bond between atoms that differ in electronegativity, electrons are pulled closer to more electronegative atom making it slightly negative and the other slightly positive

What kinds of bonds hold the monomers of a given polymer together? How are these bonds formed?

Polysaccharides: covalent bond glycosidic linkage with dehydration synthesis Proteins: covalent bond formed by dehydration synthesis Nucleic Acids: covalent bond

Be able to discuss primary structure, secondary structure, etc.

Primary structure: specific order of amino acids in proteins, can't be changed without altering order Secondary: Alpha helix and beta strand, held together with hydrogen bonds Tertiary structure: the folding that gives 3D shape; held together with: hydrogen bonds between polar side chains, hydrophobic interactions between non polar side chains, disulfide bridges, ionic bonds

Why is it more accurate to classify living things into three domains versus prokaryotic and eukaryotic?

Prok: cells that lack enclosed organelles; contain archaea and bacteria, but archaea and eukarya are actually closer related Euk: cells that contain membrane- enclosed organelles New system of archaea, bacteira, and eukarya are classified with structure, function, features, and DNA sequences

Which side chain make an amino acid acidic, basic, polar, or non-polar?

R groups: -Methyl: non-polar -Carboxyl+Hydroxyl: polar -Phosphate: charged

How and why does a misfolded hemoglobin beta-subunit (b-globin) cause red blood cells to deform? What is this disease called?

Sickle cell anemia, a common form of sickle cell disease, is caused by a particular mutation in the HBB gene. This mutation results in the production of an abnormal version of beta-globin called hemoglobin S or HbS. In this condition, hemoglobin S replaces both beta-globin subunits in hemoglobin. The mutation changes a single protein building block (amino acid) in beta-globin. Specifically, the amino acid glutamic acid is replaced with the amino acid valine at position 6 in beta-globin, written as Glu6Val or E6V. Replacing glutamic acid with valine causes the abnormal hemoglobin S subunits to stick together and form long, rigid molecules that bend red blood cells into a sickle (crescent) shape.

natural selection

The natural environment consistently selects for the propagation of certain traits among naturally occurring variant traits in the population

Be able to discuss solutions and how the chemical properties of a solvent influence the solubility of different solutes.

The pH of the solute and the solvent will affect the ability of the solute to dissolve, which will also affect overall pH of the solution. If a solute is acidic and a solvent will dissolve and emit H+ ions, making it acidic

How does a scientific theory differ from a scientific hypothesis?

Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues.

What is the difference between hypothesis, theory, and law?

Theory: possible explanation for phenomenon tested by many experiments that seem to all give the same answer Hypothesis: explanation for a phenomenon using small experiments Law: Describe phenomenon with facts and evidence

What are some examples of roles that proteins play in living things?

They are coded for by our genes and form the basis of living tissues. They also play a central role in biological processes. For example, proteins catalyse reactions in our bodies, transport molecules such as oxygen, keep us healthy as part of the immune system and transmit messages from cell to cell

Which of the following statements correctly describes cis-trans isomers?

They have variations in arrangement around a double bond.

Which of the following statements is true about buffer solutions?

They maintain a relatively constant pH when either acids or bases are added to them.

How does the theory of natural selection explain unity and diversity?

Unity: all living things descend from a common ancestor Diversity: all the descendants are very different because they adapt to their specific environments (flamingos vs penguins)

Be able to explain valance electrons and describe how they affect an element's properties?

Valence electrons: the outer most electrons of an atom involved in bonding; the number of valence electrons dictates the atom's chemical properties (boiling point, what it reacts with)

What conditions are necessary for natural selection to occur?

Variation in heritable traits, more offspring produced than the environment can sustain (competition), species are generally adapted to their environment

Natural selection: male guppies are more colorful than female guppies

Variation: some male guppies are prettier than others heritability: brightly colored males have brightly colored offspring Selection: females choose brightly colored males, also the predators choose brightly colored fish, with out predators it pays to be pretty but with predators it pays to be not too pretty

A glycosidic linkage is analogous to which of the following in proteins?

a peptide bond

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

archaean

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____.

are mirror images of each other

Starch and cellulose ________.

are polymers of glucose

In comparison to eukaryotes, prokaryotes _____.

are smaller

Water molecules can form hydrogen bonds with _____.

compounds that have polar covalent bonds

The process by which the information in a gene directs the synthesis of a protein is called ________.

gene expression

Which of the following is not a polymer?

glucose

The number of bonds an atom can form generally depends on ________.

its electron configuration

A localized group of organisms that belong to the same species is called a _____.

population

The structural level of a protein least affected by a disruption in hydrogen bonding is the

primary level.

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?

primary structure

A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound _____.

should form hydrogen bonds with water

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms?

six

Carbon dioxide in the atmosphere dissolves with the raindrops. The pH of raindrops is ________.

slightly acidic

One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3 -) and a hydrogen ion (H+). H2CO3Carbonicacid ⇌ HCO−3Bicarbonateion + H + HydrogenionH2CO3Carbonicacid ⇌ HCO3−Bicarbonateion + H + Hydrogenion If the pH of blood drops, one would expect ________.

the HCO3 - to act as a base and remove excess H+ by the formation of H2CO3

What component of amino acid structure varies among different amino acids?

the components of the R group

The partial negative charge in a molecule of water occurs because _____.

the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus

The reactivity of an atom arises from

the existence of unpaired electrons in the valence shell

Which of the following best demonstrates the unity among all organisms?

the structure and function of DNA

Organic chemistry is currently defined as

the study of carbon compounds

What are the 3 types of lipids? Be able to provide specific examples of each and to describe their function.

triglycerides (fats and oils), diglycerides (phospholipids) and steroids (estrogen and testosterone)