Shared Flashcard Set

Details

Bio 101 exam 2
not so bad
113
Biology
Undergraduate 2
10/15/2012

Additional Biology Flashcards

 


 

Cards

Term
Cells control their chemical environment using
Definition
– Energy
– Enzymes
– The plasma membrane
Term
Energy is defined as
Definition
the capacity to perform work
Term
Kinetic energy is the
Definition
energy of motion
Term
potential energy is
Definition
stored energy
Term
energy cannot be
Definition
created or destroyed (conservation of energy)
Term
energy conversion releases
Definition
Heat
Term
Heat is a
Definition
– Type of kinetic energy
– Product of all energy conversions
Term
entropy
Definition
as a measure of disorder, or
randomness.
Term
All energy conversions increase the
Definition
entropy of the universe
Term
Organic compounds are relatively rich in
Definition
chemical energy
Term
Cellular respiration is the
Definition
energy-releasing chemical breakdown
of fuel molecules that provides energy for cells to do work.
Term
A calorie is the amount of energy that
Definition
raises the temperature of
one gram of water by 1 degree Celsius.
Term
Chemical energy is
Definition
– Released by the breakdown of organic molecules during cellular
respiration
– Used to generate molecules of ATP
Term
ATP
Definition
– Acts like an energy shuttle
– Stores energy obtained from food
– Releases it later as needed
Term
Cellular work spends
Definition
ATP
Term
ATP is recycled from
Definition
ADP and a phosphate group through
cellular respiration.
Term
Metabolism is
Definition
the total of all chemical reactions in an organism
Term
enzymes,
Definition
proteins that speed up chemical reactions
Term
Activation energy
Definition
– Activates the reactants
– Triggers a chemical reaction
Term
a substrate
Definition
a specific reactant
molecule.
Term
induced fit
Definition
active site fits to the substrate, and the enzyme changes shape
slightly.
Term
Enzyme inhibitors can prevent
Definition
metabolic reactions by binding to
the active site
Term
Transport proteins
Definition
– Are located in membranes
– Regulate the passage of materials into and out of the cell
Term
Diffusion is the tendency for
Definition
molecules of any substance to
spread out into the available space
Term
Passive transport is the
Definition
diffusion of a substance across a
membrane without the input of energy
Term
concentration gradient
Definition
a region
in which the substance’s density changes.
Term
The diffusion of water across a selectively permeable membrane
is
Definition
osmosis
Term
A hypertonic solution
Definition
has a higher concentration of solute.
Term
A hypotonic solution
Definition
has a lower concentration of solute
Term
An isotonic solution has
Definition
an equal concentration of solute.
Term
Osmoregulation is
Definition
the control of water balance within a cell or
organism.
Term
Its plasma membrane may pull away from the cell wall
Definition
in the process of
plasmolysis, which usually kills the cell.
Term
Active transport
Definition
requires energy to move molecules across a
membrane.
Term
Exocytosis is the
Definition
secretion of large molecules within vesicles
Term
Endocytosis takes material into
Definition
a cell within vesicles that bud
inward from the plasma membrane.
Term
Phagocytosis (“cellular eating”);
Definition
a cell engulfs a particle and packages it
within a food vacuole
Term
Pinocytosis (“cellular drinking”)
Definition
a cell “gulps” droplets of fluid by
forming tiny vesicles
Term
Receptor-mediated endocytosis
Definition
a cell takes in very specific molecules
Term
Phospholipids
Definition
– Are key ingredients of membranes
– Were probably among the first organic compounds that formed before life
emerged
– Self-assemble into simple membranes
Term
The muscles that move our legs contain two main types of muscle
fibers:
Definition
– Slow twitch
– Fast twitch
Term
Slow-twitch fibers
Definition
– Generate less power
– Last longer
– Generate ATP using oxygen
Term
Fast-twitch fibers:
Definition
– Generate more power
– Fatigue much more quickly
– Can generate ATP without using oxygen
Term
Animals depend on plants to convert solar energy to:
Definition
– Chemical energy of sugars
– Other molecules we consume as food
Term
Photosynthesis
Definition
Uses light energy from the sun to power a chemical process that makes
organic molecules.
Term
Plants and other autotrophs (self-feeders
Definition
– Make their own organic matter from inorganic nutrients
Term
Heterotrophs (other-feeders):
Definition
Include humans and other animals that cannot make organic molecules
from inorganic ones.
Term
The ingredients for photosynthesis are
Definition
carbon dioxide and water
Term
Chloroplasts in the cells of leaves
Definition
Use light energy to rearrange the atoms of CO2 and H2O, which produces
– Sugars (such as glucose)
– Other organic molecules
– Oxygen
Term
Plant and animal cells perform cellular respiration
Definition
Primarily occurs in mitochondria
– Harvests energy stored in organic molecules
– Uses oxygen
– Generates ATP
Term
The waste products of cellular respiration are
Definition
CO2 and H2O
– Used in photosynthesis
Term
Cellular respiration is:
Definition
The main way that chemical energy is harvested from food and converted
to ATP
– An aerobic process—it requires oxygen
Term
Cells take in
Definition
oxygen gas.
– Cells release waste carbon dioxide gas.
Term
A common fuel molecule for cellular respiration is
Definition
glucose
Term
the calvin cycle makes direct use of
Definition
co2, atp, and NADPH to make sugar
Term
• Cellular respiration can produce up to
Definition
38 ATP molecules for each
glucose molecule consumed.
Term
During cellular respiration, hydrogen and its bonding electrons
change partners
Definition
Hydrogen and its electrons go from sugar to oxygen, forming water.
– This hydrogen transfer is why oxygen is so vital to cellular respiration.
Term
Chemical reactions that transfer electrons from one substance to
another are called:
Definition
Oxidation-reduction reactions or
– Redox reactions for short
Term
The loss of electrons during a redox reaction is called
Definition
oxidation.
Term
The acceptance of electrons during a redox reaction is called
Definition
reduction
Term
During cellular respiration glucose is
Definition
oxidized while oxygen is
reduced.
Term
Why does electron transfer to oxygen release energy
Definition
When electrons move from glucose to oxygen, it is as though the
electrons were falling.
– This “fall” of electrons releases energy during cellular respiration.
Term
Cellular respiration is:
Definition
– A controlled fall of electrons
– A stepwise cascade much like going down a staircase
Term
The first step is an electron acceptor called NAD+.
Definition
– The transfer of electrons from organic fuel to NAD+ reduces it to NADH
Term
The rest of the path consists of an electron transport chain,
which
Definition
Involves a series of redox reactions
– Ultimately leads to the production of large amounts of ATP
Term
All of the reactions involved in cellular respiration can be
grouped into three main stages
Definition
Glycolysis
– The citric acid cycle
– Electron transport
Term
Stage 1: Glycolysis
Definition
• A six-carbon glucose molecule is split in half to form two
molecules of pyruvic acid.
• These two molecules then donate high energy electrons to NAD+,
forming NADH.
Term
Thus, glycolysis produces
Definition
a net of two molecules of ATP per
glucose molecule
Term
The citric acid cycle
Definition
completes the breakdown of sugar.
Term
In the citric acid cycle, pyruvic acid from glycolysis
Definition
is first "prepped"
Term
The citric acid cycle
Definition
– Extracts the energy of sugar by breaking the acetic acid molecules all the
way down to CO2
– Uses some of this energy to make ATP
– Forms NADH and FADH2
Term
The Krebs Cycle
Definition
 Transfer of energy into
coenzymes NAD+ and FAD
 Substrate level
phosphorylation
Term
What comes out of the crebs cycle?
Definition
 Two molecules of CO2 from
each Acetyl co-A molecule
(4 from each glucose)
 Three molecules of NADH
from each Acetyl co-A molecule
(6 from each glucose)
 Two molecule of FADH2
from each Acetyl co-A molecule (4 from each glucose)
Term
Electron transport
Definition
releases the energy your cells need to make the
most of their ATP.
Term
electron transport chain
Definition
– The chain functions as a chemical machine that uses energy released by
the “fall” of electrons to pump hydrogen ions across the inner
mitochondrial membrane.
– These ions store potential energy
Term
When the hydrogen ions flow back through the membrane, they
release energy.
Definition
– The hydrogen ions flow through ATP synthase.
– ATP synthase:
– Takes the energy from this flow
– Synthesizes ATP
Term
Cyanide is a deadly poison that
Definition
– Binds to one of the protein complexes in the electron transport chain
– Prevents the passage of electrons to oxygen
– Stops the production of ATP
Term
• In addition to glucose, cellular respiration can “burn”:
Definition
– Diverse types of carbohydrates
– Fats
– Proteins
Term
Cellular respiration can generate up to 38 molecules of
Definition
ATP per
molecule of glucose.
Term
Fermentation is the
Definition
anaerobic (without oxygen) harvest of food
energy.
Term
After functioning anaerobically for about 15 seconds:
Definition
Muscle cells will begin to generate ATP by the process of fermentation
Term
Pyruvic acid, produced by glycolysis, is
Definition
Reduced by NADH, producing NAD+, which keeps glycolysis going.
Term
The lactic acid produced by microbes using fermentation is used
to produce:
Definition
– Cheese, sour cream, and yogurt dairy products
– Soy sauce, pickles, olives
– Sausage meat products
Term
Yeast are a type of microscopic fungus that:
Definition
– Use a different type of fermentation
– Produce CO2 and ethyl alcohol instead of lactic acid
Term
Photosynthesis
Definition
Is used by plants, some protists, and some bacteria
– Transforms light energy into chemical energy
– Uses carbon dioxide and water as starting materials
Term
The chemical energy produced via photosynthesis is stored in the
Definition
bonds of sugar molecules
Term
Organisms that use photosynthesis are:
Definition
– Photosynthetic autotrophs
– The producers for most ecosystems
Term
Chloroplasts are
Definition
– The site of photosynthesis
– Found mostly in the interior cells of leaves
Term
Inside chloroplasts are membranous sacs called thylakoids
Definition
which are suspended in a thick fluid, called stroma
Term
Thylakoids are concentrated in stacks called
Definition
grana
Term
The green color of chloroplasts is from
Definition
chlorophyll, a lightabsorbing
pigment.
Term
Stomata are tiny pores in leaves where
Definition
carbon dioxide enters and
oxygen exits.
Term
In the overall equation for photosynthesis, notice that
Definition
– The reactants of photosynthesis are the waste products of cellular
respiration.
Term
In photosynthesis:
Definition
– Electrons are boosted “uphill” and added to carbon dioxide
– Sugar is produced
Term
• During photosynthesis, water is split into:
Definition
– Hydrogen
– Oxygen
Term
Hydrogen is transferred along with electrons
Definition
and added to carbon
dioxide to produce sugar
Term
Oxygen escapes through
Definition
stomata into the atmosphere
Term
• Photosynthesis occurs in two stages:
Definition
– The light reactions convert solar energy to chemical energy
– The Calvin cycle uses the products of the light reactions to make sugar
from carbon dioxide
Term
• Chloroplasts
Definition
– Are chemical factories powered by the sun
– Convert solar energy into chemical energy
Term
Sunlight is a type of energy called radiation
Definition
or electromagnetic
energy.
Term
The full range of radiation is called the
Definition
electromagnetic
spectrum.
Term
– Chlorophyll a:
Definition
– Absorbs mostly blue-violet and red light
– Participates directly in the light reactions
Term
Chlorophyll b:
Definition
Absorbs mostly blue and orange light
– Participates indirectly in the light reactions
Term
Carotenoids:
Definition
– Absorb mainly blue-green light
– Participate indirectly in the light reactions
– Absorb and dissipate excessive light energy that might damage
chlorophyll
Term
Light behaves as photons
Definition
discrete packets of energy
Term
Chlorophyll molecules absorb photons.
Definition
Electrons in the pigment gain energy.
– As the electrons fall back to their ground state, energy is released as heat
or light.
Term
• A photosystem is a group of
Definition
chlorophyll and other molecules that
function as a light-gathering antenna.
Term
Two types of photosystems cooperate in the light reactions
Definition
– The water-splitting photosystem
– The NADPH-producing photosystem
Term
The light reactions are located in the
Definition
thylakoid membrane
Term
An electron transport chain
Definition
– Connects the two photosystems
– Releases energy that the chloroplast uses to make ATP
Term
The Calvin cycle
Definition
Functions like a sugar factory within the stroma of a chloroplast
– Regenerates the starting material with each turn
Term
C3 plants:
Definition
Use CO2 directly from the air
– Are very common and widely distributed
Term
C4 plants:
Definition
Close their stomata to save water during hot and dry weather
– Can still carry out photosynthesis
Term
CAM plants:
Definition
– Are adapted to very dry climates
– Open their stomata only at night to conserve water
Supporting users have an ad free experience!