Mitochondria + The Cytoskeleton Flashcards
(31 cards)
In the electron transport chain, electrons pass through a series of complexes with increasing…
This transfer is energetically… and the extra energy is used to pump … into the …
Electron affinity
Favourable
H+
Intermembrane Space
What had the highest electron affinity?
Oxygen!
What is the pH of the mitochondrial matrix?
What is the ph of the intermembrane space?
What does this difference result in?
8
7
Electrochemical gradient
An enzymatic complex called… found in the… membrane of the mitochondria forms a hydrophilic path through which… can flow.
The direction of flow is from… to the … which is down concentration gradient = energetically favourable!
The transmembranous domain of the complex is forced to… rather like a …
As an attached stalk grinds against the enzymatic head the… energy is converted to…
ATP Synthase Inner H+ Intermembrane space Matrix
Which process does NOT require an electrochemical gradient?
Export of CO2 from mitochondria
Where are mitochondrial proteins synthesised?
In the cytoplasm
In the mitochondrial matrix
Name the 3 types of cytoskeletal element in Oder of size.
Actin filament
Intermediate filaments
Microtubules
What are the main roles of actin, IF and microtubules?
Actin - cell shape and motility
Intermediate filaments - mechanical support
Microtubules - organelle positioning and intracellular transport
True or false: Intermediate Filament Monomers are globular.
FALSE
Typically microtubules are attached to 1 point within a cell what is this called?
MTOC - microtubule organising centre.
In animal cells this is known as the centromere!
True or false:
Monomers are added to the filaments of the cytoskeleton by covalent interactions.
FALSE
Within the cytoskeleton what is the concentration at which the rate of monomer addition EQUALS the rate of removal known as?
The critical concentration
Microtubules and Actin filaments have fast growing and slow growing end.
Name the 2 mechanisms by which this is achieved.
Nucleotide Hydrolysis
Conformation Change
Name 1 toxin or drug which affects the assembly or disassembly of the cytoskeleton.
Taxol
Phalloidin
What are examples of cytoskeletal Motor Proteins?
Kinesin
Dynein
Myosin
What is the structure with globular heads each end and a small bare section in the middle known as?
What is the middle but called?
Myosin THICK Filament
Bare Zone
Myosin head bound to… Myosin binds… … releases actin ATP… Myosin head … to move forwards … released and myosin… to actin ADP released and … (power stroke)
Actin filament ATP Myosin Hydrolysed Changes shape Phosphate, reattaches Conformation change
When Kinesins move along microtubules what causes the Trailing Head to be thrown forward?
ATP binding to leading head!
When kinesins move along microtubules (AFTER trailing head has been thrown forward) what enables the NEW trailing head to be released?
ATP hydrolysis by the NEW trailing head
Name 2 organelles held in position by the actions of Motor Proteins on microtubules.
Golgi Apparatus
Endoplasmic Reticulum
Cytoskeletal elements are central to cell motility! What forms of motility are actin and microtubules used for in the body?
Actin - muscle contraction + cell crawling + Microvilli in the gut
Microtubules - flagella and cilia
The T- antigen protein of SV40 virus contains the AA sequence
Pro-Lys-Lys-Lys-Arg-Lys-Val
What is this sequence called?
Nuclear Localisation Sequence
Typically microtubules are attached to 1 point in the cell what is it called?
MTOC / Centromere
Peroxisome numbers increase by… and reduce by…
Fission
Fusion
