Biology Ch 2

Organic vs. inorganic molecules?

-Organic molecules have carbon -Inorganic molecules don't have carbon

In a double covalent bond, a carbon atom shares

Electrons in two orbitals

What occurs when a covalent bond forms?

Electrons in valence shells are shared between atoms

Periodic table? Elements in the same column of the Periodic table have similar chemical properties. Why?

Elements in the same column of the Periodic table have similar chemical properties because they have the same number of valence electrons because they have the same number of electrons in their outer valence shell

What process exerts the pull on water molecules that is relayed from leaf to root via cohesion?

Evaporation

What is an experiment

Experiments are tests researchers make to see the outcome of a factor on a particular phenomenon.

Predict it's electronegativity compared to hydrogen,sodium and oxygenb

F>O>H>Na

Thiol (Sulfhydryl)

Forms disulfide bonds

The brackets are indicating a_____bond

Hydrogen

The unequal sharing of electrons within a water molecule makes the water molecule ____

Polar

What is the matter?

- matter is anything and everything that has mass and volume -Matter is made of elements (atoms) -Elements cannot be broken down

Atomic number vs. mass number? What are they based on? What is the difference between them?

-Atomic number is the number of protons in the nucleus -The mass number is the number of protons and neutrons in the nucleus

What are buffers? How does the carbonic acid/bicarbonate buffering system work? Why is this buffering system important for acidification of the ocean?

-Buffers are weak acids or bases that can react with strong acids or bases to prevent sudden changes in pH -buffering system important for acidification of the ocean because as the concentration of dissolved carbon dioxide increases, the rate of the forward reaction of the buffering system increases until the system reaches a new equilibrium. This means that an increase in dissolved carbon dioxide causes a slight decrease in pH.

Why does carbon have a special place in biology and biochemistry?

-Carbon has a special place in biology and biochemistry because biologically important molecules consist of long carbon chains -Carbon chains vary in size, length, structure, shape, etc.

the valences of carbon and its most frequent partners (= how many bonds they create in organic molecules)

-Carbon valence is 4 electrons -its most frequent partners are hydrogen, oxygen and nitrogen

Chemical reactions - what are reactants, products, catalysts/enzymes?

-Chemical reactions occur when chemical bonds between atoms are formed or broken -Reactants is the original substance before it undergoes a chemical reaction -Products is the final result of the substance after it undergoes a chemical reaction -Catalyst a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. -Enzymes is a type of catalysts

What are the four water properties that facilitate an environment for life?

-Cohesive behavior of water molecules The molecules "stick" together due to hydrogen bonds -Ability to moderate temperature The molecules adapt to the temperature the molecules move faster when it's in the gas form -Expansion upon freezing The molecules space out when they freeze -Versatility as a solvent It pores in almost everything

Electron shells - what are they? How does the energy of electrons within different layers differ from each other? What is the valence shell? What is an orbital?

-Electrons shells are shells that surround the nucleus of an atom. -The valence shell is the outermost shell of an atom. -Orbital are regions of space around the nucleus of an atom where an electron is likely to be found. -Electrons are distributed as: 1st level - 2 electrons max 2nd level - 8 electrons max Each following level 8 electrons max

What is energy? Types of energy? (mechanical, chemical, light, potential, thermal, electromagnetic)

-Energy- capacity to do work, or put matter into motion. Types of energy -Mechanical energy - directly involved in moving matter -Chemical energy -stored in chemical bonds of substances -Potential energy- stored energy -Electromagnetic energy - energy that travels in waves -Kinetic energy- Energy in action -Light energy is a kind of kinetic energy -Thermal energy - internal energy of an object due to the kinetic energy

What are the functional groups?

-Functional groups are organic molecules that are most commonly involved in chemical reactions -Functional groups containing oxygen and nitrogen are good at gaining or losing proton

What are the six functional groups that are most important in the chemistry of life:

-Hydroxyl group (-OH) hydroxyl groups makes compounds more soluble in water. Lose protons in solutions Alcohol -Carbonyl group (C=O) Carbonyl groups allow molecules to react and form large and complex compounds. Aldehyde and ketone polar -Carboxyl group (-COOH) acts as an acid Carboxylic acid tend to attract or drop a proton -Amino group (-NH2) Acts as a base Amine tend to attract or drop a proton -Sulfhydryl group(--SH) thiol -Phosphate group (O-O-P=O-O) Phosphate groups store chemical energy that can be used in chemical reactions. Organic phosphate

Isomers - what are they? Structural, geometric, enantiomers)

-Isomers are compounds with the same formula but different structures. -Structural isomers - different covalent (the atoms are connected in a different order) -Geometric - same covalent -Enantiomers - mirror images

What is an isotope? Radioisotopes and half-life? How do isotopes of the same element differ from each other?

-Isotope is when the same element had different structural variations -Isotopes of the same element differ from each other due to different amount of neutrons -Radioisotopes are isotopes that have unstable nuclei and undergo radioactive fail. -Half-life is the length of time required for half of the radioactive atoms in a sample to fail

Most atoms are not "happy" by themselves. Why? Are there elements that are "happy"? Do you think they would participate in chemical bonding?

-Most atoms are not happy because their valence shell is not complete. -Yes there are happy elements: He,Ne, Ar, Kr,Xe, and Rn -Happy elements do participate in chemical bonds but with each other

What is the difference between natural and artificial selection?

-Natural selection has to do with an individual's characteristics that are heritable and can be reproduced a lot -artificial selection is done by what feature we want an organism to have more than another feature and that's done through breeding.

What types of chemical bonds are there? How do they differ? (polar covalent, nonpolar covalent, ionic, hydrogen, Van der Waals interactions) What types of elements are known to participate in each type of chemical bond?

-Nonpolar covalent Electrons bonds are shared equally between 2 atoms No chargers on atoms Weak bonds Carbon and Hydrogen Nonpolar molecules: Benzene, Octane, and Methane -Polar covalent Electron bonds are shared unequally between 2 atoms Partial charge on atoms Strong bonds Oxygen Glucose is polar molecule so it dissolves rapidly in water -Ionic Transfer of electrons Full chargers on resulting ions Ions - is when an atom loses or gains an electron -Hydrogen Can be found in DNA and protein Water molecules are hydrogen Hydrogen are nonpolar molecules -Hydrophobic tend to be nonpolar prefer other neutral molecules and nonpolar solvents Weak interactions between mostly carbons and hydrogens

History of where different species come from.

-Pluto believed everything is perfect -Aristotle believed there is an order from where species come from -Lamark believed there are changes in generations -Darwin believed that all species are related by common ancestry (descent with modification)

Hydrogen bonds

-Polar covalent bonds in water molecules result in hydrogen bonding -Hydrogen bonds are hydrophilic

Evolution

-Population is a group of individuals of the same species -Adaptation is a trait that helps an organism survive and reproduce -Fitness is how well an organism can survive and reproduce in its environment -Evolution is the change in characteristics of population overtime -natural selection is the process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. -Speciation occurs when population diverge to form new species

Water has an unusually high specific heat. What does this mean?

-The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C. -Water's high heat capacity is caused by hydrogen bonding among water molecules.

Polar covalent ? Why is water a polar molecule?

-The water molecule is a polar molecule because the opposite ends have opposite charges -Polarity allows water molecules to form hydrogen bonds with each other

Make sure you can explain how selection works using the examples of white fur mice and the TB- causing microorganisms

-Two conditions must be met for natural selection to occur in a population -Individuals must vary in characteristics that are heritable/passed on -Certains traits help individuals reproduce more than other versions -Natural selection acts on individuals -Evolutionary change occurs in populations -Acclimation is when 1 species changes -Adaptation is when the whole population changes

Does natural selection act on individuals or populations? So then, how can something that gives an advantage to certain INDIVIDUALS change the makeup of the whole POPULATION

-Yes, natural selection acts on individuals or populations -Certain heritable traits leads to increased success in producing offspring which means traits become more common in a population over time.

What is the difference between acclimatization and adaptation?

-adaptation is when the whole population changes -acclimation is when 1 species changes

The occurrence of transitional fossils supports the idea that

-change occurs in species over time. -extinct and living forms are related. -these are the ancestors of living species.

What are the four emergent properties of water that are important for life?

-cohesion -moderation of temperature -expansion upon freezing -solvent properties

What is the difference between an element and a compound? What is a molecule of an element? What is a molecule of a compound? What are mixtures?

-elements cannot be broken down by chemical substances -compounds consist of 2 or more elements. -Molecules are atoms attached to each other by chemical bonds. -Molecules of element: bonds between the same element ex: O2 -Molecules of compounds: bonds between different elements ex: H2O

What is the pH of a strong acid? What is the ph of a strong basic solution? Give examples.

-pH of a strong basic solution is 7+ Examples: ammonia -pH of a strong acid is 7 or lower Examples: lemon juice

An electrically neutral molecule has the formula C3H4O2N, If the carbon atoms form the usual number of bonds , How many covalent bonds will each hydrogen atom have with other atoms in the molecule ?

1

Alcohol ( Hydroxyl)

1) Polar 2) Can make a compound more soluble in water

Based on the following information ( specific heat) which of the following statements are true ?

1)Benzene is more resistant to temp change than sulfuric acid 2)Water has a high specific heat due to the hydrogen bonding between water molecules 3)More heat is required to raise the temp of 1 g of water 1 c than to raise the temp of 1 g of ethyl alcohol 1 c

Surface tension

1)Cohesive force caused by the attraction between the molecules at the surface of a liquid 2)A water strider runs across a pond without breaking the surface tension 3)A sewing needle floats when it is placed gently on top of water in a bucket

Cohesion

1)Water molecules are attracted to each other 2)A drop of water spilled on a table forms a drop on the table rather than spreading out over the surface 3)Molecules at the surface hydrogen-bond with water molecules next to them and below them

Adhesion

1)Water molecules cling to plant cells 2)Water molecules cling to the side of a beaker 3)Partial positive charges on water molecules at the perimeter adhere to the negative charges on glass resulting in an upward pull

Flourine's atomic number is 9 & it's atomic mass is 19. How many neutrons does fluorine have ?

10

An atom has 8 protons, 8 neutrons, and 8 electrons. Another isotope of the same element might have ...

10 neutrons

An atom of oxygen has an atomic number of 8. How many electrons are in the first, second, and third electron shells, respectively?

2, 6, 0

The following reaction produces water as one of the products. What molecular formula completes the equation ( 2CO2 + 4H2 - CH3COOH + ?)

2H2O

An atom's atomic number is 7. Its valence is most likely ...

3

This atom can form up to _____ single covalent bond(s).

4

In molecules, C, H, O, and N atoms usually make __, __, __, and __ bonds respectively. a. 4, 1, 3, 2 b. 3, 2, 1, 4 c. 2, 1, 3, 4 d. 3, 2, 4, 2 e. 4, 1, 2, 3

4, 1 , 2 , 3

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have ?

5

What is the atomic number of an atom that has 6 protons , 6 neutrons, & 6 electrons ?

6

The mass number of an atom is 15, and its atomic number is 7 . The atom probably has _____

8 neutrons in the nucleus

Dr. Jones says an atom has 3 electrons in the first shell and four electrons in the second shell. Someone should tell Dr. Jones that ... a. the first shell shouldn't have 3 electrons b. the second shell can't have 4 electrons c. the first shell must fill before the second shell can have electrons d. no shell can hold more than 2 electrons e. the second shell should have 8 electrons

A

Without making or breaking bonds, the pictured molecule can change its shape because ... a. rotation can occur around single bonds b. some atoms make longer bonds than others c. proximity of other atoms alters bond angles d. electrons can move from one bond to another e. None of the above

A

What is the hypothesis? How do we state hypothesis?

A hypothesis is a testable statement that explains something observed A hypothesis needs to be focused and testable

Why does water have a high specific heat

A water molecule can make 4 hydrogen bonds.

What molecules show an appropriate number of bonds around each carbon atom?

A,B,E

According to the theory of evolution by natural selection, fitness is a measure of an organism _____.

Ability to produce viable, fertile offspring

Amine (Amino)

Acts as a base

Carboxylic Acid (Carboxyl)

Acts as an acid

What is ATP? What does the abbreviation stand for?

Adenosine Triphosphate - ENERGY - is required for active transport.

What is Cell Theory? What does it say?

All-cells-from-cells Cells are produced when pre-existing cells grow and divide Spontaneous generation The belief that cells arise spontaneously under certain situations

What functional group behaves as a base

Amino group

A substance that gives up a proton during a chemical reaction , raising the hydrogen ion concentration of water is most appropriately called

An acid

which statement is true of the atom shown in the diagram

An electron will move from the outer to the inner shell. The atom is in the excited state The atom has more than one valence electron

Which solution is acidic?

Any solution with a pH lower than 7

Atom - definition, structure, subatomic particles - proton, neutron, electron - where do they reside within an atom, what is their size and charge?

Atom Structure Nucleus : protons + neutrons Electrons

To fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add ... a. 1 electron b. 2 electrons c. 3 electrons d. 8 electrons e. Can't tell without knowing which element it is

B

What is biology? What does it study?

Biology is the study of all living things

BONDS - what are they? How are they created? Why are they created?

Bonds are formed when atoms share electrons, they are created because of the need of the element needing to fill their valence shell.

By making two covalent bonds, an O atom (with 8 protons) fills its valence shell. Why does the atom's charge stay close to zero? a. The atom has 8 electrons b. The valence shell has 6 electrons c. Shared electrons aren't always near oxygen d. The atom lost electrons from other shells e. The charge isn't near zero; it's -2

C

Two C atoms form a double bond. Each C is bound to two H atoms. Which statement is true? a. The bonds orient like tripods or pyramids b. The bonds orient in a tetrahedral fashion c. All the atoms lie in a plane d. All the atoms lie in a line e. The groups rotate around the C=C bond

C

An atom has 6 electrons, 6 protons , & 6 neutrons . You can tell that this atom belongs to the element _______ Because_______

C, It has 6 protons

Which of the following molecules would you predict to have the largest number of polar covalent bonds based on their molecular formula ?

C3H6O ( Acetone) C3H8O (Propanol) C3H8(Propane) C3H6O2(Propionic acid) !

What is a carbonyl group?

C=O

What is a carboxyl group?

COOH

carbon & hydrogen

Carbon and hydrogen have the same electronegativity

What defines living things? 5 characteristics

Cells (all organisms have cells) Energy (all organisms acquire and use energy to stay alive) Evolution (population of organisms is constantly evolving) Replication (all organisms are capable of reproducing) Hereditary information

What are cells?

Cells are the basic building and functional units of living organisms

Organic Phosphate (Phosphate)

Contributes to negative charge

The ammonia molecule in the diagram has the observed bond orientation because ... a. N has four pairs of electrons in the valence shell b. electrons repel one another c. N has 7 protons in its nucleus d. All of the above e. None of the above

D

A phrase that applies to covalent bonding and not other kinds of bonds is

Electron - sharing

Covalent Bond

Electron pairs are shared

What is true of atoms?

Electrons determine the atoms size

Electron distribution and chemical properties?

Electrons determine the chemical behavior of an atom

Water is a source of ______________ for chemical reactions in cells.

Hydrogen atoms and oxygen atoms

hydrophobic vs. hydrophilic interactions. How does that affect how protein molecules fold?

Hydrophobic Can not interact with water Repelled by water Nonpolar Lipids Long chains of hydrogen and carbon Hydrophilic Can interact with water Attracted to water Can form dipole dipole interactions or hydrogen bonds with water Polar

In salt what is the nature of the bond between sodium and chlorine?

Ionic

What name is given to the bond between water molecules?

Ionic

What is true of water's tensile strength

It results from hydrogen bonding, It helps to pull water through plants, It involves both cohesion and adhesion

Aldehyde (Carbonyl)

May be a structural isomer of a ketone

A __________ refers to two or more atoms held together by covalent bonds

Molecule

What factor is important in making it possible to cool yourself by sweating

Molecules collide with varied angels and speeds and hydrogen bonds are relatively weak

Which molecules are hydrophilic?

Molecules containing primarily non-polar covalent bonds

Does evolution always work toward a "BETTER" organism?

No

Is hydrogen bonding possible between two hydrophobic molecules?

No, hydrogen bonding between molecules occurs between water molecules.

You find a bacterium growing in pure oil, containing the usual hydrophobic lipids. This organism must be very good at breaking down _____.

Nonpolar covalent bonds

Match the monomers with their polymers.

Nucleic acid polymers are made up of nucleotide monomers. Carbohydrate polymers are made up of simple sugar monomers Protein polymers are made up of amino acid monomers.

What is a hydroxyl group?

OH-

State the number and type of bond you expect F>O>H>Na would form if it reacted with sodium

One ionic bond

What is a phosphate group

PO4

In this molecule , what type of bond is found between the oxygen and hydrogens

Polar covalent

Water is a polar molecule because of the presence of ___________ bonds.

Polar covalent

Which kinds of bonds are present in a single water molecule?

Polar covalent bonds

Which types of molecules readily dissolve in water?

Polar molecules and hydrophilic molecules

Why doesn't oil mix with water?

Polar molecules attract one another.

What is the prediction?

Prediction is an observable result that must be correct if a hypothesis is valid Example: if it is cloudy, it will rain

Which model accurately represents the current view of the structure of the atom

Probability

Atoms of a specific element always have a constant number of _____.

Protons

Chemists assign atoms to chemical elements by counting their

Protons

What kind of bond joins the carbon atom to each of the hydrogen atoms

Single (non-Polar Covalent)

What group is a characteristic of thiols

Sulfhydryl group

Highlight all the atoms of the FOUR functional groups

Sulfhydryl, Phosphate , Hydroxyl , Amino

Why isn't the insect drowning?

Surface tension

What determines the types of chemical reactions that an atom participates in ?

The number of electrons in the outermost electron shell

Which property is shared by living things but not with a rock?

The rock doesn't have cells, doesn't use energy, doesn't grow, it doesn't reproduce and it doesn't respond to changes in the environment.

Two atoms always represent the same element if they have....

The same number of protons

How does the pH of the solution on the right compare with that of the solution on the left?

The solution on the right is basic relative to the solution on the left

What is true of the energy levels of electrons in shells ?

The valence shell has higher energy than other occupied shells

Why do carbon atoms tend to make 4 covalent bonds

The valence shell needs 8 electrons

What is a theory?

Theory is an observation that are supported by many evidences

Which of these refers to atoms with the same atomic number but different atomic masses?

These atoms are isotopes

What is vitalism?

Vitalism is a theory that says that the origin of life is dependent of chemical or physical forces.

Which of the following statements is a theory according to the scientific usage of the word?

Weather is caused by the movement of air over the surface of the Earth.

Partial charges occur when ...

a covalent bond links atoms of two kinds and atoms share electrons unequally.

What is the tree of life? What does it represent? How is it constructed?

a family tree of organisms

Solution

a homogeneous mixture of the substance that is dissolved

Dissolving is best described as ...

a mingling of molecules and/or ions.

acid

a substance that loses hydrogen ions as it dissolves in pure water, thus resulting in a solution with high hydrogen ion concentration. Therefore, an acid is likely to serve as a proton donor to other substances.

What does it mean "hydrophobic"?

afraid of water polar

Which functional group contains nitrogen

amino

Radioactive decay is likely to occur when

an atom has too many neutrons.

An ionic bond involves _____.

an attraction between ions of opposite charge

the open spaces in waters crystal structure make it possible for

aquatic life to exist at the north pole

Atoms with the same number of protons but with different electrical charges_______

are different ions

How are carbon-based molecules different from inorganic molecules?

carbon based molecules contain hydrogen unlike inorganic

Which functional group behaves as an acid

carboxyl groups

What is another name for a condensation reaction

dehydration

How was vitalism disproved?

disproved by heating an inorganic compound with another inorganic compound urea without the aid of a living organism or part of a living organism

A _______ bond joins these two oxygen atoms

double covalent

The tendency of an atom to pull electrons toward itself is referred to as its

electronegativity

Covalent bonds are due to the sharing of _____

electrons

Covalent bonds hold atoms together because they

fill shells without giving atoms much charge and bring electrons closer to protons.

Each water molecule is joined to _____ other water molecules by ____ bonds.

four , hydrogen

electrons in higher shells

have more energy than the ones in the inner shells

Why does water have surface tension

hydrogen bonds between surface water molecules resist being stretched.

What is the arrow pointing to?

hydrogen ion

In a neutral solution the concentration of

hydrogen ions is equal to the concentration of hydroxide ions

What is the name of the process during which a bond between two monomers is broken

hydrolysis

What is the arrow pointing to?

hydroxide ion

Why does the temp of boiling water remain constant even with added heat

it takes energy to break hydrogen bonds

Is hydrogen bonding possible between two hydrophobic molecules?

no

What is pH scale? How is it established?

pH scale is the shifting of hydrogen between 2 water molecules

What group has a major role in energy transfer

phosphate group

Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface

polar groups attract one another

isotope

radioactive isotope releases energy

What do elements with atomic numbers 6, 14, and 22 have in common?

same number of valence electrons and will form the same number of covalent bonds

Solvent

the dissolving agent of a solution

Which of these relationships is true of an uncharged atom?

the number of protons is equal to the number of electrons

Solute

the substance that is dissolved

In a glass of old-fashioned lemonade, which is the solvent?

water

The hydrogen bonds among water molecules endow water with which property

water has a high specific heat

Why is ice less dense than water?

water molecules make hydrogen bonds at definite angels and cold molecules move less than warm ones