Exam 1 Flashcards
______ _______ result from the arrangement and interaction of parts within a system; characterize nonbiological entities as well
Emergent Properties
_______ is the reduction of complex systems to simpler components that are more manageable to study.
EX; the molecular structure of DNA
Reductionism
A ____ is a combination of components that function together.
system
____ _____ constructs models for the dynamic behavior of whole biological systems.
Systems Biology
What are the 3 approaches to study biology?
reductionism, emergent properties, systems biology
What are the levels(in order) at which we study life?
biosphere, ecosystem, community, population, organism, organ system, organ, tissue, cell, organelle, molecule, atom
What are the activities that cells must perform to be alive?
homestasis, organization, metabolism, growth, adaptation, response to stimuli, reproduction
Regulation of the internal environment to maintain a constant state EX: sweating to reduce temp.
Homeostasis
Being structurally composed of one of more cells, which are basis units of life
Organization
Transformation of energy by converting chemicals and energy into cellular components and decomposing organic matter
Metabolism
Maintenance of a higher rate of anabolism than catabolism; a growing organism increases in size in all of its parts
Growth
The ability to change over time in response to environment; fundamental process of evolution
Adaptation
often expressed by motion
Response to stimuli
The ability to produce new individual organisms, either asexually from a single parent, or sexually from two parents
Reproduction
_____ are an organism’s basic unit of structure and function
cells
_____ are the lowest level of organization that can perform all activities required for life
cells
all cells are enclosed by a _____ and use ___ as their genetic information.
membrane; DNA
The ____ __ ___ ___ ___ is the basis of all reproduction, growth, and repair of multicellular organisms
ability of cells to divide
A _____ cell has membrane-enclosed organelles, the largest of which is usually the nucleus
eukaryotic
A _____ cell is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles
prokaryotic
Bacteria and Archea are
prokaryotic
plants, animals, fungi, and all other forms of life besides bacteria and arches are
eukaryotic
The continuity of life is based on heritable information in the form of
DNA
Chromosomes contain most of a cell’s genetic material in form of ____
DNA
DNA is the substance of
genes
Each _____ has one long DNA molecule w/ hundreds or thousands of genes
chromosomes
How if DNA inherited?
From parents to offspring
DNA controls the ____ and _____ of organisms
development and maintenance
Each DNA molecule is made up of two long chains arranged in a
double helix
Each link of a chain is one of four kinds of chemical building blocks called
nucleotides
Genes control ____ production indirectly
protein
DNA is transcribed into ____ then translated into a protein
RNA
An organism’s _____ is its entire set of genetic instructions.
genome
observe and describe some aspects of the world and use inductive reasoning to draw general conclusions
discovery science
based on observations, scientists propose hypothesis that lead to predictions
hypothesis-based science
Matter is made up of ______
elements
An _____ is a substance that cannot be broken down to other substances by chemical reaction
element
A _______ is a substance consisting of 2 or more elements in a fixed ratio.
compound
A compound has characteristics that are _____ from those of its elements
different
About __ of the 92 elements are essential to life
25
What makes up 96% of living matter?
Carbon, Oxygen
The remaining 4% of living matter consists of….
calcium, phosphorus, potassium, and sulfur
____ elements are those required by an organism in minute quantities.
Trace
An element’s properties depend on the ____ of its atoms
structure
An atom is the _____ unit of matter that still retains the properties of an element
smallest
What are the subatomic particles of atoms?
protons, neutrons, and electrons
Neutrons have what charge?
neutral/none
protons have what charge?
positive
electrons have what charge?
negative
neutrons and protons are located where in an atom?
in the nucleus
electrons are located where in an atom?
they form a cloud around the nucleus
neutron mass and proton mass are almost _____ and are measured in daltons
indentical
An element’s ______ number is the number of protons in its nucleus
atomic
An element’s ______ number is the sum of protons and neutrons in the nucleus
mass
______ are the same element with the same # of protons but differing neutrons
isotopes
Isotopes are two atoms of an element that differ in the # of _______
neutrons
Radioactive isotopes decay spontaneously giving off ______ and _____
particles; energy
What are some applications of radioactive isotopes in biological research?
dating fossils, tracing atoms through metabolic processes, and diagnosing medical disorders
____ is the capacity to cause charge
energy
_____ energy is the energy that matter has because of its location or structure
potential
The electrons of an atom _____ in their amounts of potential energy
differ
An electron’s state of potential energy is called its ______
energy level or shell
The chemical behavior of an atom is determined by…
the distribution of electrons in electron shells
The ____ ____ shows the electron distribution for each element
periodic table
____ electrons are those the outermost shell.
valence
The _____ _____ of an atom is mostly determined by the valence electrons
chemical behavior
Elements with full valence shell are chemically ____
inert
An orbital is the 3D space where an ____ is found 90% of the time
electron
An electron shell consists of a specific number of _____
orbitals
The _____ and _____ of molecules depends on chemical bonding between its atoms
formation and function
Atoms with incomplete valence shells can ____ or ____ valence electrons with certain other atoms
share; transfer
Interactions in which atoms share or transfer valence electrons usually result in atoms staying close together, held in place by attractions called ______ _____
chemical bonds
A _____ bond is the sharing of a pair of valence electrons by two atoms
covalent
A ____ covalent bond is the sharing of one pair of valence electrons
single
A ____ covalent bound is the sharing of two pairs of valence electrons
double
Covalent bonds can form between…
atoms of the same element or atoms of different elements
A _____ is a combo of 2 or more different elements
compound
Bonding capacity is called an atom’s ____
valence
______ is an atom’s attraction for the electrons in a covalent bond
electronegativity
The more electronegative an atom is the more _____ it pulls shared electrons towards itself
strongly
In a _____ covalent bond the atoms share the electron equally
non polar
In a ____ covalent bond one atom is more electronegative and the atoms do not share the electrons equally
polar
what is the most electronegative atom?
oxygen
What element is the perfect sharer?
carbon
Un equal sharing of electrons a partial positive or negative charge for each atom or molecule called what?
a pole
Bond in which atoms strip electrons from their bonding partners are called what?
ionic bonds
A charged atom is called an ___
ion
A positively charged ion is called what?
cation
A negatively charged ion is called what?
anion
Compounds formed by ionic bonds are called ionic compound or
salts
Most of the strongest bonds in organisms are _____ binds that form a cell’s molecules.
covalent
Some examples of weak chemical bonds are…
ionic bonds and hydrogen bonds
Weak chemical bonds serve what purpose?
reinforce shapes of large molecules and help molecules adhere to each other
A ____ bond forms when a hydrogen atom covalently bonded to an electronegative atom is also attracted to another electronegative atom
hydrogen
In living cells the electronegative partners are usually ______ or _______
oxygen or nitrogen
If electrons are distributed ______ in molecules they can result in “hot spots” of positive or negative charge
asymmetrically
This asymmetrical distribution between molecules that are close together causes….
Van der Waals interactions
Van der Waals interactions alone are ____ but a bunch of them together can be extremely _____.
weak; strong
A molecule’s ____ is very important to its function
shape
A molecule’s shape is determined by what?
the positions of its atoms’ valence orbitals
_______ _____ are the making an breaking of chemical bonds.
chemical reactions
The ____ molecules of a chemical reaction are called reactants
starting
The final molecules of a chemical reaction are called _______
products
What does it mean that some chemical reactions go to completion?
all reactants are converted into products
All chemical reactions are _____
reversible
What does it mean for a chemical reaction to be reversible?
Products of the forward(original) reaction become reactants for the reverse reaction
Chemical equilibrium is reached when what happens?
the forward and reverse reaction rates are equal
_____ appears to be unique to our earth?
water
Water covers _____ of the Earth’s surface.
three-fourths
Water constitutes ______% of the living world.
60-70
Water is regenerated and redistributed through ______.
evaporation
Water exists in _ ____ in the natural world.
3 states
Water us ______ to life because dehydration kills very quickly.
essential
What is the structure of water?
one O covertly bonded with 2 H’s
What is the bond angle of water?
105 degrees
Oxygen is _______ and attracts the electrons of hydrogen.
electronegative
Unequal distribution gives water ______
polarity
The oxygens have a slight _______ charge
negative
The hydrogens have a slight _____ charge
positive
The polar nature of water allows for water to be seen in nature as ____ _______.
3 states
Liquid water has fragile, disorganized _______ bonds.
hydrogen
Liquid water’s bonds only last a few ______ of a second
trillionth
The bonds of liquid water are constantly _______
reforming
Solid water has _____ hydrogen bonds.
organized
Crystal is more ____ than disorganized liquids which is why ice floats.
spacious
The structure of ____ water molecules is single molecules liberated from other by the addition of energy.
gaseous
Collectively, hydrogen bonds hold water molecules together a process called ______
cohesion
Cohesion helps the transport of water against ______ in plants.
gravity
______ is an attraction between different substances, for example, between water and plant cell walls
adhesion
____ ______ is a measure of how hard it is to break the surface of a liquid; related to cohesion
surface tension
Water absorbs heat from _____ air and releases stored air to _____ air.
warmer; cooler
Water can absorb or release a large amount of heat with only a slight change in its own _____
temperature
The behavior of water is the basis for the ______ temperature scale
metric
A _____ is the amount of heat required to raise the temperature of 1 gram of water by 1 degree celsius
calorie
Calories on food packages are actually _____
kilocalories
The ____ ______ of a substance is the amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature 1 degree celsius
specific heat
The specific heat of water is what?
1 cal/g/degree C
Water ____ changing its temperature because of its high specific heat.
resists
Water’s high specific heat can be traced to _____ _____.
hydrogen bonding
Heat is _____ when hydrogen bonds breaks
absorbed
heat is _____ when hydrogen bonds form
released
The high specific heat of water_______ temp. fluctuations to within limits that permit life.
minimizes
______ is the transformation of a substance from a liquid to a gas.
evaporation
The heat a liquid most absorb for 1 gram to be converted to gas
heat of vaporization
As a liquid evaporates its remaining surface cools, this is a process called ______ _______
evaporative cooling
Evaporative cooling of water helps stabilize _____ in organisms and bodies of water
temperatures
Ice floats in liquid water because _____ bonds in ice are more ordered making ice less dense than water
hydrogen
water reaches its greatest density at what temperature?
4 degrees celsius
If all ice sank, all bodies of water would eventually freeze solid making…
life on Earth impossible to sustain
solvent + solute =
solution
Water is a versatile solvent due to its _____
polarity
Water’s polarity allows it for easily form ______ bonds
hydrogen
When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called a ______ ____
hydration shell
Water can dissolve compounds made of ______ polar molecules
nonionic
Large molecules such as proteins can dissolve in water if they have ….
ionic and polar regions
hydrophilic substances =
substances with an affinity for water
hydrophobic substances =
substances that do not like water
oil molecules are hydrophobic because they have relatively _____ bonds
non polar
a stable suspension fine particles in a liquid
a colloid
Most biochemical reactions occur in ____
water
Chemical reactions depend on _____ of molecules and therefore on the ____ of ____ in an aqueous solution
collisions;concentration;solutes
_____ mass is the sum of all masses of all atoms in a molecule
Molecular
Numbers of molecules are usually measured in _____
moles
1 mole =
6.02 times 10^23 molecules
6.02 times 10^23 is what?
avogadro’s number
The number of moles of solute per liter of solution
Molarity
Water is in a state of ______ _____
dynamic equilibrium
What is dynamic equilibrium?
a state in which water molecules dissociate at the same rate at which they are being reformed
The dissociation of water molecules has a ____ effect on organisms.
great
The hydrogen atom in a hydrogen bond between 2 water molecules can….
shift from on hydrogen to the other
A hydrogen molecule with a extra proton is called what?
Hydronium ion
A hydronium ion is often represented as
H+
When a hydronium ion is created the molecule that lost a proton is called what?
hydroxide ion
A hydroxide ion is often represented as
OH -
Changes in concentration of H+ and OH- can ______ affect the chemistry of a cell
drastically
Acidic solutions have a pH of ____ than 7
less
Basic solutions have a pH of ____ than 7
greater than
Bases have a higher concentration of ___ ions.
H+
