FINAL Flashcards
What is not a characteristic of living things?
Conduction of Heat
Viruses present a challenge in determining what is either living or non-living because they…
Exhibit characteristics of life but only when they have infected a cell
What is one of Charles Darwin’s observations?
Many of the traits in an individual are heritable
What provides evidence of the common ancestry of all living things on Earth?
All cells store genetic information in DNA
What is a substance that cannot be broken down into other substances by a chemical reaction?
Element
If you change (add or subtract) the number of electrons in an atom, you create ____________.
an ion
What are the naturally occurring elements that make up 96% of the mass of an organism?
Oxygen, Hydrogen, Carbon, and Nitrogen
An _________ is the smallest unit of matter that still retains the properties of an ____________.
atom, element
If you change the number of protons in an atom, you create _________.
A different element
Which of the following best describes the relationship between the atoms described below?
Atom 1: Atom 2:
1 H 3 H
1 1
They are isotopes
The naturally occurring element Bromine has an atomic mass of 80 mass units (amu) and contains 45 neutrons. What is the atomic number of Bromine?
35
What does the chemical behavior of an atom depend on?
The electrons in the outer energy shell of the atom
In an atom, the electrons are arranged in distinct energy levels or shells. Electrons in shells that are farther away from the nucleus have ________ potential energy than electrons in shells that are closer to the nucleus.
more
A covalent bond is considered polar when…
one of the atoms sharing electrons is much more electronegative than the other atom
When are atoms most stable?
When the valence shell is completely filled with electrons
In a molecule of methane (CH4):
The bonds between C and H are covalent and the electrons are shared equally
What kind of atom is most likely to form an anion with a charge of -1?
One with a full valence shell of electrons.
The movement of water from the roots to the leaves in a tree is possible due to what property resulting from its molecular structure?
The cohesion between water molecules that results from hydrogen bonding
When heat is absorbed by liquid water, what will happen to individual water molecules?
hydrogen bonds between water molecules will be broken
Because of its ability to hydrogen bond to itself, the temperature of water changes _______ other substances when water absorbs heat.
less than
A mole of sucrose (sugar) and a mole of caffeine are equal in their…
number of molecules
the partial negative charge at one end of a water molecule in attracted to the partial positive charge of another water molecule. What is this attraction called?
a hydrogen bond
The mass of one molecule of sucrose is 342 mass units (amu). A mole of sucrose is equivalent to what?
342g
Which of the properties of water is extremely rare when compared to other substances?
Ice floats on water
An _________ is a substances that decreases the hydrogen ion [H+] concentration of an aqueous solution.
Base
What is the hydrogen ion concentration [H+] of a solution with a pH of 10?
10^-10 M
A given solution contains 0.001 (10^-3) moles of hydrogen ions [H+] per liter. What best describes this solution?
Acidic with a pH of 3
A solution with a pH of 6 has how many more hydrogen ions (H+) in it than a solution with a pH of 7?
10 times
the chemical equation for the formation of Hydronium and Hydroxide ions in pure water can be simplified to represent the dissociation of water. What is the correct equation for the dissociation of water?
H2O —> OH- + H+
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when places in an aqueous solution, dissociates into bicarbonate ion (HCO3-) and a hydrogen ion (H+).
If the pH of blood increases, one would expect_______.
A decrees in the concentration of H2CO3 and an increase in the concentration of H+
The results from Stanley Miller’s 1953 experiments can best be used to support what hypothesis?
Organic molecules can be synthesized abiotically under conditions that may have existed on early Earth.
Why are hydrocarbons insoluble in water?
The majority of their bonds are non polar covalent carbon-to-hydrogen bonds.
Increasing amounts of the greenhouse gas CO2 are produced as a result of the combustion of fossil fuels. About 25% of the human generated CO2 becomes dissolved in the ocean. What is the effect of the pH of the ocean resulting from increased amounts of this gas?
The pH is decreased
Carbon can form up to ______ bonds with other atoms making it a very versatile atom. This is a major reason why life is based on this element.
4
hydrophobic substances such as vegetable oil are…
non polar molecules that repel water molecules
Which of the following molecules has the fewest characteristics of an organic molecule?
Methane, Keratin, Water, Hemoglobin, or Cellulose?
WATER!!!!
Thalidomide is a medication for the treatment of nausea and was used extensively in the 1950s and 1960s by expecting mothers. The birth defects that were related to use of the medication was due to what property of this drug?
The form of the drug responsible for birth defects is an enantiomer
Glucose and Fructose both have the molecular formula C6H12O6. Glucose and Fructose are…
Structural isomers
What is true of carbon?
It can form both polar and non polar bonds
In order for a molecule to be an enantiomer, there must be an asymmetric carbon atom. What is an asymmetric carbon?
The carbon atom has formed covalent bonds with four different chemical groups
A functional group that cells use as a source of energy that can drive biological reactions is…
a phosphate group
Emergent properties…
result from the interactions of parts within a system.
Ex.) the interactions between the population and environment in an ecosystem; Organisms adapting and evolving to suit their environments.
One unique property resulting from the structure of water molecules is that ice floats on water. Why is this important?
Solid water is less dense than liquid water, it insulates the water below it as it floats, allowing moron life to flourish. If ice was more dense, life would freeze and die in the ocean.
What functional groups are found in the building blocks of proteins?
Hydroxyl, carboxyl, amino, sulfhydryl, carboxyl, and methyl
What class of biological molecules are NOT polymers?
lipids
TRUE or FALSE
The primary structure of a protein determines its 3-D shape or conformation
true
Proteins are macromolecules made up of subunits called _______ and bound together by covalent _______ bonds.
amino acids, peptide
A single nucleotide in DNA or RNA consists of what?
A nitrogenous base, a phosphate group, and a 5 carbon sugar
Proteins perform what function in cells?
Enzymes, transport, hormones, structural.
Interactions between the _________ of a polypeptide are primarily responsible for the formation of a protein’s tertiary structure.
side chains
When nucleotides are joined to form a polynucleotide strand _________.
A covalent bond forms between the sugar of one nucleotide and the phosphate of a second
What best summarizes the differences between DNA and RNA?
RNA contains the base uracil, whereas DNA contain the base thymine
The double helical structure of DNA consists of two polynucleotide strands that are held together by ________ bonds between paired ________.
hydrogen, bases
Biological molecules that have the general formation of CH2O are:
Carbohydrates
TRUE or FALSE
The enzymes in animals and humans that digest polysaccharides can break down glycogen, starch, and cellulose
False
In polysaccharides, the monosaccharide subunits are connected by what type of covalent bond?
glycosidic bond
Carbohydrates perform what functions in cells?
Storage of energy
What property is shared by all lipids?
They are hydrophobic
What is true of both starch and glycogen?
They are long chains of glucose molecules connected together.
Saturated fats…
Contain only carbon-hydrogen single covalent bonds
How do phospholipids interact with water molecules?
the polar heads interact with water; the non polar tails do not
What structure is common to plant and animal cells?
Mitochondrion
Cell size is limited by…
The ratio of the surface area to volume
A cell with an extensive area of smooth endoplasmic reticulum would be expected to…
synthesize large quantities of lipids
What is common to both prokaryotic and eukaryotic cells?
ribosomes
Collection, packaging, and sorting of molecules synthesized in the cell is a function of the…
Golgi apparatus
Tay-Sachs disease is a human genetic disease that results in cells that are unable to break down (digest) a specific type of lipid. Which cellular organelle must be involved in this condition?
The lysosome
The membrane of the endoplasmic reticulum is continuous (directly connected to) what?
the Nuclear Envelope
Where are ribosomes found in the cell?
In the cytoplasm and on the rough endoplasmic reticulum