Unit 2 Flashcards
Cells are
the structural, functional, and reproductive units of life
Cell Theory
life from life
Biodeegenisiis
Scans the surface
Sem
Transmission penetrates
‘through’ structure
Tem
magnifies many thousand
times larger than actual size
* And improves resolution
TEM
SEM
EM
Most cells and cell parts are between how many microns
1-100 microns
Transport is both facilitated and limited by the
Plasma Membrane
The area of membrane must be great enough to meet needs
of cytoplasm’s metabolic requirements
Small
* Less structurally complex
* No nucleus
Prokaryotic Cells
Large (relative to prokaryotes)
* Structurally complex
* Nucleus
Eukaryotic
Double membrane
* Nuclear ‘pores’ (points of
passage through membrane
Nuclear Envelope
Function as sites of protein synthesis
Ribsosomes
Provides compartmentalization of cytoplasm
– Segregation of function
– Isolates and concentrates reactants, enzymes
– Synthesis, modification, packaging
EMS
Internal membrane continuous with the
nuclear envelope
Endoplasmac reticulum
involved in lipid synthesis
– Also in detoxification of poisons in liver cells
– Calcium storage in muscle cells
Smooth ER
produces protein
– Distributes protein into membranous
sacs called Vesicles
Rough Er
Prepares for shipment to destination inside or
outside (from the trans side
Gogli Apparatus
Vesicles containing digestive enzymes
Lysosomes
Plant cells have a
– Provides turgidity
Central Vacuole
Energy Conversion Organelles
(not part of the EMS)
Mitochondria
Energy Conversion Organelles
(not part of the EMS)
Chloroplast
Energy Conversion Organelles
(not part of the EMS)
Perixomews
site of cellular respiration
– Double membrane
* Outer membrane and highly folded inner membrane
* Folds of the Inner membrane called Crista
Mitochondira
site of photosynthesis
– Double membrane organelle
– Inner membrane folded into sacs called Thylakoids
* Contains chlorophyll for photosynthesis
Chloroplast
A network of fibers throughout the cell
* Functions:
– Provide support, shape to cell
– Motility
– Cellular junctions
Cytoskeleton
contraction, crawling,
pinching
Microfilaments
cilia, flagella, centrioles
(mitotic spindle
Microtubles
between cells,
no leakage between
(as in epithelia cells
of the skin
Tight Junctions
lexible point attachments
Desmosomes
channels between cells
(nutrients like sugar
and amino acids may pass,
communication between cells
Gap funnctions
Connects cytoplasm in
plant cells
* Similar to ‘Gap
Junctions’ in animal cells
Plasmodesmata
integrated within the
phospholipid bilaye
Transmembrane
are associated with the inner
surface
Peripheral protiens
results in movement of
Molocules
defined as movement across a
permeable membrane
Transport
indicates movement of molecules is driven by
diffusion
Passive transport
have hydrophilic inner
‘tunnel’ thru which polar and ionic
molecules may pass unimpede
Channel protiens
attach and shuttle
molecules across membrane, undergo a
subtle shape chang
Carrrier protiens
the passive transport of H2O
Osmosisi
channel proteins that facilitate
H2O transport at high rate
Aquaporins
describes the direction of movement into or out of a
cell; a cell may gain or lose water depending on the
surrounding aqueous solution
Tonicity
solute concentration outside
cell is lower than solute inside of ce
Hypotonic
solute concentration
outside of cell is higher than solute inside cell
Hypertonic
Red blood cell in marine water shrinks and
shrivels up (crenate
Hypertonic
Metabolic energy is used to pump molecules
across the membrane
* against the gradient, or
* at a rate GREATER than the rate of
diffusion
Active Transport
allows cells to maintain
concentration gradients that differ from their
surroundings
Active Transport
transport protein that
generates voltage across a membrane
electrogenic pump
pumps help store energy that can
be used for cellular work
Electrogenic Pumps
Bulk transport across the plasma membrane
occurs by
Exocytosisi and endocytosis
transport vesicles migrate to
the plasma membrane, fuse with it, and
release their contents
exocytosis
the cell takes in
macromolecules by forming new vesicles
from the plasma membrane
endocytosis
Energy may be transformed or transferred,
but neither created nor destroyed
First Law Of Thermodynamics
With each energy transformation and
transferral, some energy will be transformed
into thermal energy
Second Law
Energy available to do work (G) i
Free Energy
release free energy
– products have less free energy than reactants
– products are more stable than reactants
Spontaneous reactions
Only ______can be used to do work
Spontaneous reactions
Reactions that release energy are
Exergonic Reactions
Energy stored in chemical bonds is
released when bonds are broken
Exergonic Reactions
reactions require an input of
energy
Endergonic
Bonds are formed, energy input, stored
Endergonic reactions
is the breaking down of
complex molecules
– Bonds broken, energy released (exergonic
rxs)
– Produces metabolites
Catobolism
is the building of complex
molecules from smaller components
– Bonds are formed, energy input (endergonic
rxs)
– Uses metabolites
Anabolism
The transfer of a phosphate
group to reactant molecule, making it more
reactive (less stable
Phosphorolation
regeneration
of ATP from ADP and phosphate
Catoblic reactions
any substance that increases
the rate of a chemical reaction
Catalyst
Organic catalysts utilized by
biological systems to increase the rate of
metabolic reaction
Enzymes
Is the reactant an enzyme acts on
The substrate
Forms when the enzyme binds to its substrate
enzyme-substrate complex
Temperature
– pH
– Concentration of substrate
– Presence of regulators
activity of an enzyme is affected by
general environmental factors
Regulation of enzymes is means of
regulation of
Metabolsim
activate
or inhibit enzyme activity from
site other than active sit
Allosteric Regulators
catabolism of
glucose
C ellular Respiration
Breakdown of glucose is coupled to
the
synthesis of ATP
Hydrolysis of ATP is COUPLED
to cellular
work
– transport, mechanical, chemical work
Coenzymes are organic
Cofactors
to ‘shuttle or
carry’ item downstream in pathway
Coenzymes
Oxygen is
highly electronegative
causes the oxidation of another molecule
– becomes reduced in the process
– oxygen is NEVER oxidized, nothing pulls
electrons from it
Oxygen
A series of redox reactions transfer pairs of
electrons from one molecule to another
ETS
glucose + oxygen → carbon dioxide + water + energy
Aerobic Cellular Respiration
Pathway divided into 3 stages
– Glycolysis
– Krebs Cycle (a.k.a. Citric Acid Cycle)
– Electron Transport System (ETS)
ACR
Glucose enters cell by Facilitated Diffusion
* Enzymes in cytoplasm catalyze the splitting of
glucose (lysis)
* One C-6 molecule → Two C-3 molecules
Glycolosis
As glucose is split, electrons are removed
(first Redox reaction)
* There to accept the electrons are molecules
of the coenzyme NAD+ (first reduction rx)
* Product of reduction is NADH
– NAD+ + 2e- (plus a proton)→ NAD
Oxidation of Glucose
TP is formed by ‘phosphorylating’ ADP
– Source of phosphate varies
* If transferred from organic (substrate):
– substrate-level phosphorylation
– as in glycolysi
Phsoporolation
Glucose (C6) + 2 ATP + 2 NAD+ →
2 Pyruvate (C3) + 2 NADH + 4 ATP
Glycolosisi
Pyruvate (C3) is oxidized as it is transported into the mitochondrion (matrix) – transition stage
Krebs Cycle
Carboxyl groups are removed
– CO2 molecules produced and released as waste
2nd Stage
Krebs
This type of reaction is a DECARBOXYLATION
Rx
Krebs
Oxidizes the acetyl group from pyruvate
– Occurs in the matrix of the mitochondri
Citric Acid Cycle ( Krebs)
2 Pyruvate (C3) → 6 Carbon dioxide (CO2)
+ 2 ATP + 6 NADH* + 2FADH2
Krebs Cycle
Electron Transport Chain is a series of molecules
embedded in the CRISTAE
3rds stage of Aerobic respiation
These molecules receive electrons handed off from the
coenzyme
ETC
Final
Electron Acceptor
Oxygen
The energy released in thel’
transfer is INDIRECTLY used to
synthesize ATP
Downhill
Chemiosmosis is coupled DIRECTLY to
ATP Sythasis
Electron Transport Chain is INDIRECTLY used to
Sythasisi ATP
energy released by the electron transport chain
(Redox) is used to transport (pump) H+ across the
inner membrane of the mitochondrion
Chemiosmosis
he
driving force the results from
the electrochemical gradient
Proton Motive Force
Electrons (from numerous coenzymes) + 2 O2 →2 H2O
+ Energy (26 to 28 ATP)
ETS
ATP from glycolysis
2
ATP From Krebs Cycle
2
ATP (from ETS)
26 to 28
Glucose + 2NAD+ +2ATP → 2Pyruvate + 2NADH + 4ATP
Alohol fermentation
A phospholipid bilayer that encloses the entire organelle.
Outer membrane
A second phospholipid bilayer that surrounds the stroma,
which is the fluid-filled interior of the chloroplast.
Inner mEMBRANE
Name the organelles found in a plant cell that are NOT found in animal cells.
Chloroplasts, Cell wall, Large central vacuole, Plasmodesmata, Amyloplasts.
The space inside the inner membrane that contains mitochondrial
DNA, ribosomes, and enzymes involved in the citric acid cycle, which is also
involved in producing ATP.
Matrix
The —– is a complex, dynamic network of interlinking protein filaments
present in the cytoplasm of all cells, including those of bacteria and archaea.
Cytoskeleton
The hydrolysis of ATP IS
EXERGONIC
moving against gravity. Not a free fall
Mechanical:
movement across a membrane. Diffusion driven
transport. Not all transport is work
Transport
Endergonic chemical reactions that require energy. Dehydration
reactions.
Chemical
Energy (like money) may be ‘invested’ to increase ‘yield’
2 ATP’s are used (investment), but 4 ATP’s are produced (yield)
-2 ATP plus 4 ATP = 2 ATP (net yield)
Excellent investment (double your money)
Electron Transport Chain is a series of molecules embedded in the
Chrstae
The energy released by the electron transport chain (Redox) is used to transport
(pump) H+ across the inner membrane of the mitochondrion
Chemiosmosisi
source of potential energy used to drive
ATP synthesis (an endergonic reaction)
Electrochemical gradient
the driving force the results from the electrochemical
gradient
Proton motive force
As the H+ diffuse back, (thru the enzyme ATP synthase) energy is released and
used to drive the endergonic reaction:
ADP + P →ATP
As the H+ diffuse back, (thru the enzyme ATP synthase) energy is released and
used to drive the endergonic reaction:
ADP + P →ATP
