Term
| What are the two types of specialized cells in the retina? |
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Definition
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Term
| Which photoreceptor works best in bright light? |
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Definition
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Term
| Which photoreceptor works best in dim light? |
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Definition
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Term
| What are a small fraction of cells that detect light/dark and cues circadian rhythm? |
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Definition
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Term
| In most places to the eye what has to happen to the pathway of light before reaching photoreceptors? |
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Definition
| First has to go through ganglion cells ad retinal neurons. |
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Term
| What is the function of the cornea? |
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Definition
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Term
| What is the function of the lens? |
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Definition
| changes shape in order to focus and direct light |
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Term
| What are the thin layer of cells lining the back of the eye |
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Definition
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Term
| Where is it apparent that the cells of the eye are specialized? |
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Definition
| Molecular and organelle level. |
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Term
| What is the portion of the brain the retina and nerves send signals to? |
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Definition
| Lateral Geniculate Nucleus (GLN) |
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Term
| T/F: The retinal signals are sent to the same part on the same side of the brain? |
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Definition
| False! Right and Left signals are sent to separate layers in the LGN. |
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Term
| Why would you want to keep the information in separate places of the brain? |
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Definition
| Coordination and depth perception |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| False! They see lack of detail (B+W) |
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Term
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Definition
| False! They see details (color) |
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Term
| Which are far more numerous? Rods or Cones? |
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Definition
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Term
| Where is the distribution of Rods more predominant? |
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Definition
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Term
| Where is the distribution of Cones more predominant? |
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Definition
| In the central retina (Fovea) |
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Term
| Where does light not have to pass through cells in order to get to the photoreceptors? |
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Definition
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Term
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Definition
| The optic nerve head where the photoreceptors are absent. |
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Term
| Where is the vision the clearest and has the most distinct vision? (can see details) |
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Definition
| Macula (Fovea is part of the macula) |
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Term
| The cytoskeleton is a non-membranous organelle that serves what function? (5) |
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Definition
1. Cell shape 2. Strength 3. Locomotion
4. Chromosome separation (mitosis/meiosis) 5. Intracellular transport of organelles |
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Term
| What are the three cytoskeleton elements from smallest to largest? |
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Definition
| smallest: Microfiliments Intermediate Filaments Microtubules :largest |
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Term
| What are microfilaments made of? |
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Definition
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Term
| What are the functions of Microfilaments? |
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Definition
- Connects organelles to membranes
- Influences cell motility and strength
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Term
| What are Intermediate Filaments made of? |
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Definition
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Term
| What is the function of Intermediate filaments? |
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Definition
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Term
| What are Microtubules made of? |
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Definition
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Term
| What are the functions of Microtubules? |
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Definition
- Influence cell structure and shapr
- Motility (such as organelle movement or cilia/ Flagella)
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Term
Label a. b. and c.
[image] |
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Definition
a. Microfilaments
b. Intermediate filaments
c. Microtubules |
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Term
| Which cytoskeleton element provides the supporting framework within the cell? |
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Definition
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Term
| These are located just beneath the plasma membrane |
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Definition
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Term
| Responsible for the organization and function of microvilli. |
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Definition
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Term
| Keratins, Lamins, neurofilaments and vimentins are all types of what? |
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Definition
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Term
| What is the (basic) structure of a microtubule? |
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Definition
| 25nm hollow cylinders made by a ring of 13 "protofilaments" |
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Term
| Why do microtubules use GTP? |
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Definition
| To grow by polymerization of tubulin dimers |
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Term
| How do Microtubules shrink? |
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Definition
| depolymerization (release of tubulin dimers) |
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Term
| Which micrutubule end is "+" and the other "-"? |
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Definition
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Term
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Definition
| One end of a microtubule is growing, while the other is shrinking |
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Term
| What are the two groups of microtubule motors? |
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Definition
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Term
| Which way do kinesins move? |
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Definition
|
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Term
| Which way do dyneins move? |
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Definition
|
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Term
|
Definition
| orthogonal arrangement of two centrioles |
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Term
|
Definition
| Barrel-shaped microtubule structure (made fo 9 microtubule triplets) |
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Term
| What is the arrangement of microtubules in a cilium or flagella? |
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Definition
| The same pattern of centrosomes (9 sets of 3 microtubules) |
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Term
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Definition
| whip-like structures that undulate to move cells |
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Term
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Definition
| Hair-like structures that sweep fluids across cells (more cargo with microtubules) |
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Term
| T/F: Cilium can "feel" what's going on in cells? |
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Definition
| True! Primary cilium enable cells to respond to mechanical stimuli |
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Term
| What is the photoreceptor outer segment made of? |
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Definition
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Term
|
Definition
| Relative consistency of the internal environment |
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Term
| Define: "Negative Feedback" |
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Definition
| the stimulus is down-regulated or turned off. |
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Term
| What are functions of the Plasma Membrane? |
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Definition
| Works as a barrier, shipping and receiving, security checkpoint, identification and communication. |
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Term
| What is the composition of the plasma membrane? |
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Definition
| Phosphoglycerides, Sphingolipids, Sterols |
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Term
| What is an "amphipathic structure"? |
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Definition
| Includes a polar "head" group and two fatty acid "tails" |
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Term
| What is the plasma membrane made of? |
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Definition
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Term
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Definition
| Phospholipids that naturally assemble to hide the hydrophobic tails from water. |
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Term
| What is the barrier function of plasma membranes? |
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Definition
| Reduces the diffusive flux of H2O (10,000 times!) |
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Term
| Is rhodopsin located in rods or cones? |
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Definition
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Term
| Where is rhodopsin located in the photoreceptor? |
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Definition
| Rhodopsin sits in the rod disc membrane |
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Term
| Define: Potential Difference (PD) |
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Definition
| The electrical voltage change across the plasma membrane |
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Term
| The Resting membrane potential (RMP) depends on what 2 parameters? |
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Definition
Transmembrane Ion gradients (particularly K+ and Na+)
Membrane permeability of those ions |
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Term
| Resting Membrane Potential of Na+ is (High/low) on the inside of the cell and (High/low) on the outside of the cell |
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Definition
Low on the inside
High on the outside |
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Term
| Resting Membrane Potential of K+ is (High/low) on the inside of the cell and (High/low) on the outside of the cell |
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Definition
High on the inside
Low on the outside |
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Term
| What is used to pump Na out and K in? |
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Definition
| active transporters of Na,K-ATPase |
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Term
| What does the steady state mean? |
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Definition
| "Pumps out what comes in" |
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Term
| What 2 opposing forces happen to K ions as soon as they move? |
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Definition
Chemical force (push K out)
Developed electrical force (pulls K in) |
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Term
| The outwardly-directed K+ gradient results in a... |
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Definition
| Inside negative electrical potential |
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Term
| An inside negative PD determined mostly by ___ is a characteristic of cells in their _____ _____ |
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Definition
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Term
| T/F There's always an equal concentration of - and + therefore, no charge across PM |
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Definition
| False!!! There is still a charge across PM |
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Term
| Why is there still a charge across PM when Ion concentrations are the same? |
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Definition
| Because the ions adjacent to the PM are slightly different |
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Term
| What does the Nernst equation represent? |
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Definition
| The theoretical balance between forces of a single ion |
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Term
| How does Goldman equation represent the real situation? |
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Definition
Other ions such as Cl are involved
Ionic permeabilities can change |
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Term
| At rest permeability of what predominates? |
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Definition
|
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Term
| In the Dark, photoreceptros are (Hyperpolarized/Depolarized)? |
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Definition
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Term
| In a flash of light, photoreceptros are (Hyperpolarized/Depolarized)? |
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Definition
|
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Term
| Na Channels are open or closed in the dark? |
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Definition
|
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Term
| Na Channels are open or closed in the light? |
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Definition
|
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Term
| What is the light sensitive molecule in the photoreceptor? |
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Definition
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Term
| Rhodopsin is what kind of receptor? |
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Definition
| G- protein coupled receptor |
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Term
| Activation of Rhodopsin gets rid of cGMP and closes which ion channels? |
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Definition
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Term
| G-alpha activates ________ which leads to hydrolysis of _____. |
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Definition
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Term
| If _______ is present, Na channels are open. |
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Definition
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Term
| Rhodopsin activation leads to cell (hyperpolarization/depolarization)/ |
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Definition
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Term
| Rhodopsin activation also stops the release of which neurotransmitter? |
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Definition
|
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Term
| Where in the mitochondria are proteins that generate ATP located? |
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Definition
|
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Term
|
Definition
| Whether ion channels are open or closed |
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