LESSON 3a: The Mitochondrion (Structure) Flashcards
3 main kind of cell work
- Mechanical Work
- Transport work
- Chemical work
beating of cilia,
muscular contraction,
chromosome movement during
cell division
Mechanical work
pumping of
substances across membranes
Transport work
synthesis of
polymers from monomers
Chemical work
Energy is stored in organic molecules namely:
carbohydrates, fats, proteins
eat organic molecules
Heterotrophs
Heterotrophs eat these organic molecules —> food digest organic molecules to get…
-raw materials for synthesis
-fuels for energy
“burning” fuels in a series of _____________
step-by-step
enzyme-controlled reactions
_______________ of glucose to produce ATP
catabolism
model of harvesting stored energy
Glucose
Formula for respiration
Glucose + Oxygen —> Energy + Water + Carbon dioxide
Chemical formula of respiration
C6H12O6 + 6O2 —> ATP + 6H20 + 6CO2 + heat
making a lot of heat
energy by burning fuels in one step
combustion
making ATP (& some heat)
by burning fuels in many small steps
respiration
___________ move electrons by
shuttling H atoms around
Electron carriers
Moving electrons in respiration
– NAD+ –> NADH (reduced)
– FAD+2 —> FADH2 (reduced)
Features of ATP
-Bonds between phosphate
groups unstable and broken by
hydrolysis
-High energy phosphate bonds
– term is misleading
-Phosphate bonds in ATP
actually weak and unstable;
products of hydrolysis ( ADP
and ℗ more stable
-Release of energy during ATP
hydrolysis from a chemical
change to a more stable
condition and not from
phosphate bonds themselves
Why are phosphate bonds unstable?
-All three phosphate groups negatively charged
-Like charges crowded together ; repulsion contributes to
instability of bonds
-Triphosphate tail of ATP chemical equivalent of a loaded
spring; release/relaxation of compressed spring
releases energy
The energy currency of the cell
Adenosine Triphosphate (ATP)
The energy transducers
Mitochondria ang Chloroplasts
- Act similar to electric power plant
- Up to 300 to 800 per cell
- Can replicate itself
- Come from cytoplasm in EGG
-Found in eukaryotic
cells - A membranous
organelle - Has its own DNA
(circular) and proteins. - Three parts: outer
membrane, inner
membrane and matrix - The outer membrane is
permeable to pyruvate.
Mitochondria
You inherited your mitochondria
from your _________
mother
Three parts of mitochondria
-Outer membrane
-inner membrane
-matrix
The outer membrane of mitochondria is permeable to _________
Pyruvate
Mitochondria is same size as ________ which is?
Bacteria (0.5-1.0 microns wide, up to 10 microns long)
Parts of mitochondria: fairly smooth
Outer membrane
Parts of mitochondria: twisted
Inner membrane
Parts of mitochondria: Infoldings of inner membrane
Cristae
Parts of mitochondria: Substance located in space formed by inner membrane
Matrix
_________differ in length, shape and number depending on the cell’s
energy needs
Cristae
In ______ cristae go halfway across mitochondrion
Most cells
Short cristae represent ______________
low energy requirements
In __________, cristae cross all of the way
Muscle cells
Muscle cells also have ________ cristae
tightly packed
In muscle cells, more cristae represent _______________
high energy requirements
high level
of oxidative phosphorylation
Condensed
low level of oxidative
phosphorylation
Orthodox
Most cristae are arranged in
__________
shelves
In steroid secreting cells, the
cristae are __________
tubular
shelf cristae halfway through the
organelle
Typical mitochondria
Tubular or circular cristae
Steroid secreting cell mitochondria
tightly packed shelf cristae crosses organelle
Active mitochondria
- Mitochondria in dendrite
- Up to 25µm
Longitudinal section
- Are accumulations of calcium phosphate
- Helps maintain low levels of calcium ions
in the cytosol
Matrix Granules
Mitochondria replicate by __________ like
bacterial cells
simple fission
Most mitochondria situated close to parts of cell that have_______________
highest energy
requirements
More mitochondria are found in cells that:
– have motile machinery
– sequester low pH substances
– pump large amounts of ions
Fewer mitochondria are found in cells that operate under __________
anaerobic
conditions
Small lymphocytes have a ______
while hepatocytes have about ________
-few
-1000
– “white fiber”
– Fast twitch
– Works under anaerobic
conditions (glycolysis)
Type II skeletal muscle fiber
– Especially those that are
no longer dividing
– Protective function
Skin epithelia (stratified
squamous keratinizing
epithelia)
– Glycogen is broken down to yield energy via the glycolytic
pathway of glucose oxidation
– Citric acid cycle less important
– They have lysosomes, BUT……
– Surviving anaerobically is advantageous since they can
kill bacteria and clean debris in poorly oxygenated areas
*Inflamed or necrotic tissue
Neutrophil
Glycogen is broken down to yield energy via the ________________
glycolytic pathway of glucose oxidation
- A cell with just about every
organelle in abundance - Very metabolically active cell
- Detoxifies, produces bile
Hepatocyte
- High energy
requirement - Especially the “red”
fibers
Skeletal Muscle
Continuous contraction
requires a lot of ATP
Cardiac Muscle
- Produces the HCl of the stomach
- In the epithelia lining
- These are the cells targeted by
Pepcid AC, Tagamet and
Zantac*-
– indirectly - Mitochondria are needed to
sequester the H + - ATP is needed to move the microtubules in the
cilia - Cilia helps move mucus along in the lumen of
the trachea and the ovum in the oviduct
Parietal cell of the stomach
Mitochondria are needed to
sequester the ____
H+
____ is needed to move the microtubules in the
cilia
ATP
________helps move mucus along in the lumen of the trachea and the ovum in the oviduct
Cilia
Vesicles contain _________
neurotransmitters
Mitochondria furnish energy for
___________
synaptic activity
___________ has same microtubule
arrangement as cilia
Flagellum
Flagellum requires ________ to move
ATP
Mitochondrial inheritance of
defects is _________ because few,
if any, mitochondria enter the
ovum with the sperm head
maternal
- Kidney filtration
- Sodium ions diffuse passively
through apical membrane - Ions actively transported out of
the cells by a
sodium/potassium ATPase
located in the basement
membrane - These cells also provide for
protein digestion
Cells of proximal convoluted
tubule
Sodium ions diffuse passively
through ___________
Apical membrane
Ions actively transported out of
the cells by a
______________
located in the basement
membrane
sodium/potassium ATPase
- Heat production is increased in this
tissue because mitochondria in these
cells have a transmembrane protein
called thermogenin in their inner
membrane - Energy is dissipated by heat and
warms blood in nearby capillaries
Brown adipose
Heat production is increased in this
tissue because mitochondria in these
cells have a transmembrane protein
called _____________- in their inner
membrane
thermogenin
Mitochondria convert
cholesterol into
pregnenolone* which is
converted into steroids
in the sER
Cortisol secreting
cell of adrenal cortex
- The visual process requires a lot of energy
- Protein synthesis and energy conduction
Rods and Cones of the Eye
Advantage of highly folded inner
membrane?
More surface area for membrane-bound enzymes & permease
Without mitochondrion ATP production would ____________________________________
cease and the cells would not be able to function
Four types of function by the inner membrane that contains protein
- Those that carry out the
oxidation reactions of the
respiratory chain - ATP synthase, which use
the H+ gradient to make
ATP - Specific transport
proteins that regulate the
passage of metabolites
into and out of the matrix - Protein import machinery
- it contains enzymes. It can catalyze
ATP to create ADP.
-symbolic enzyme: adenylate kinase
intermembrane space
symbolic enzyme in intermembrane space
Adenylate Kinase
-Enzymes are abundant in here. It also contains mitochondrial genetic system including DNA and ribosome.
- some reaction pathways take place in the here.
-symbolic enzyme: malic acid dehydrogenase.
Matrix
Symbolic enzyme in matrix
malic acid dehydrogenase
-it also call ATP synthase.
-it lies in the inner membrane
elementary particle
