Unit 2: Ch 3 (Cellular Form & Function) Flashcards
1
Q
Vesicular Transport*
- Description
- Vesicle processes
A
- Processes and moves large particles, droplets, or molecules at once through the membrane
- Active primary transport
-
Endocytosis
- Bring matter into a cell
- Phagocytosis: “Cell eating”; large solids
- Pinocytosis: “Cell drinking”; smaller volumes, usually liquid
- Receptor-mediated: Specific protein or ligand is required for transport
-
Exocytosis
- Release matter from a cell
- Motor proteins energized by ATP
-
Transcytosis
- Matter brought into, through & removed from cell
- Sum or process of both exocytosis and endocytosis
-
Endocytosis
2
Q
Active transport
- Description
- Types
A
- The movement of molecules across the cell membrane against the concentration gradient with the assistance of ATP
-
Primary active
- Directly uses ATP by transferring a phosphate group to the transport protein
-
Uniport: Carries only 1 type of solute
- Sodium-Potassium pump
- Exocytosis
- Endocytosis
- Transcytosis
-
Secondary active
- Transport of solute particles up their concentration gradient, by a carrier that doesn’t use ATP; indirectly uses ATP
- Cotransport/Symport: Carries 2+ solutes in same direction
- Countertransport/Antiport: Carries 2+ solutes in different directions
-
Primary active
- Reference
3
Q
Aquaporins*
A
- Proteins that move water from one side of a cell membrane to another
- Cells can increase the rate of osmosis by installing more aquaporins in the membrane or decrease the rate by removing them
4
Q
ATPase Pump*
A
- Moves sodium (Na) and potassium (K) ions across the cell membrance in an active transport process involving the hydrolysis of ATP to provide the necessary energy
- Responsible for maintaining the large excess of Na+ outside the cell and the large excess of K+ ions on the inside
- It accomplishes the transport of 3 Na+ to the outside of the cell and the transport of 2 K+ ions to the inside; left with a net charge of -1
- This unbalanced charge transfer contributes to the separation of charge across the membrane
- The sodium-potassium pump is an important contributor to action potential produced by nerve cells
- Notes
- Sodium
- An extracellular ion
- Found in high concentrations extracellularly
- Moves down the gradient
- Extracellular ion that moves 3+ charges to ICF
- Potassium
- Found in high concentrations intracellularly
- Intracellular ion that moves 2 ions to ECF
- Sodium
5
Q
Carrier-Mediated Transport*
A
- A solute binds to a carrier in the plasma membrane, which then changes shape and releases the solute to the other side
- Transport protein required for movement (pH and temperature sensitive)
- Don’t chemically change their ligands
- Specificity: Only carries specific ligands
- Saturation: Transport maximum (Tm)
6
Q
Cell Components*
A
- Plasma membrane (aka cell membrane & plasmalemma)
- Cytoplasm
- Nucleus
7
Q
Cell Structure Identification*
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/724/006/q_image_thumb.png?1614433232)
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/724/006/a_image_thumb.jpg?1614433243)
8
Q
Cell surface extensions
A
- Aid in the absorption, movement, and sensory processes
- Include:
- Microvilli
- Cilia
- Flagella
- Pseudopods
9
Q
Cellular Membrane Transport
A
- Controls the passage of materials into and out of the organelles and cells
- Selectively permeable
10
Q
Centrioles*
A
- Organelle that helps move genetic material
- Forms mitotic spindle during cell division
- 9 + 3 pattern (9 groups of 3)
11
Q
Centrosome
- Function
- Appearance
A
- Organizing center for the formation of microtubules of cytoskeleton and mitotic spindle
- Clear area near nucleus containing a pair of centrioles
12
Q
Channel Proteins
A
- Allow water and hydrophilic solutes to move through the membrane
- Leak channels: Always open and allow materials to pass through continually
- Gate channels: Open and close under different circumstances and allow solutes through at some times, but not others
13
Q
Cilia*
A
- Move substances across the superior border of a cell
- Nonmotile & motile
- 9 + 2 pattern (9 groups of 2)
- Widespread sensory roles (equilibrium, smell, vision)
14
Q
Clathrin
A
- Serves as an “address label” on the coated vesicle that directs the vesicle to an appropriate destination in the cell
15
Q
Cristae
A
- A crista is a fold in the inner membrane of a mitochondrion
- Increases surface area, which increases area for chemical reactions and diffusion to occur on
- Aids aerobic cellular respiration, because the mitochondrion requires oxygen
16
Q
Cuboidal
A
- Squarish-looking in frontal sections and about equal in height and width
- Example: liver cells
17
Q
Cytoskeleton Structure Identification (1 of 2)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/730/705/q_image_thumb.png?1614439669)
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/730/705/a_image_thumb.jpg?1614439679)
18
Q
Cytoskeleton Structure Identification (2 of 2)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/730/632/q_image_thumb.png?1614439544)
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/337/730/632/a_image_thumb.jpg?1614439570)
19
Q
Cytoskeleton*
- Function
- Components
A
- Determines the shape of the cell
- Made of proteins
- Function
- Lends structural support
- Directs movement of substances through the cell (transcytosis)
- Contributes to the movements of the cell as a whole
- Components
- Microfilaments (smallest size)
- Intermediate fibers (middle size)
- Microtubules (largest size)
20
Q
Diffusion
A
- The net movement of particles from a place of high concentration to a place of lower concentration as a result of their constant, spontaneous motion
- Diffuse down their concentration gradients
21
Q
Diffusion Rates*
- Description
- Influencing factors
A
- Determine how quickly a cell can acquire nutrients or rid itself of wastes
- Factors impacting the rate of diffusion:
- Temperature
- Molecular weight
- The steepness of the concentration gradient
- Membrane surface area
- Membrane permeability
22
Q
Endocytosis*
- Description
- Forms
A
- Active primary transport
-
Phagocytosis
- Only occurs in a few specialized cells
- Process of engulfing particles such as bacteria, dust, and cellular debris large enough to be seen with a microscope
- “Cell eating”
-
Pinocytosis
- “Cell drinking”
- Process of taking in droplets of ECF containing molecules of some use to the cell
- Occurs in all human cells
-
Receptor-mediated endocytosis
- Enables a cell to take in specific molecules from the ECF with a minimum of unnecessary matter
- Particles in the ECF bind to specific receptors on the plasma membrane. The receptors cluster and the membrane sinks in, creating a pit coated with a membrane protein called clathrin
-
Phagocytosis
23
Q
Endoplasmic Reticulum (ER)*
- Description
- Types
A
- System of interconnected channels; “little network within the cytoplasm”
- 2 types:
- Rough ER (rER)
- Synthesizes proteins
- Smooth ER (sER)
- Does not modify proteins because it does not have any ribosomes
- Synthesizes & modifies lipids and carbohydrates
- Rough ER (rER)
24
Q
Role of Plasma Membrane Enzymes
A
- Breaks down a chemical messenger and terminates its effect
- Note
- Enzymes in the plasma membrane carry out the final stages of starch and protein digestion in the small intestine, help produce second messengers and break down hormones and other signaling molecules whose job is done, thus stopping them from excessively stimulating a cell
25
Q
Exocytosis
A
- Process of eliminating material from a cell by means of a vesicle approaching the cell surface, fusing with the plasma membrane, and expelling its contents
- Used to release cell secretions, replace worn-out plasma membrane, and replace membrane that has been internalized by endocytosis
- Examples
- Golgi Complex/Apparatus
26
Q
Extensions of the cell surface
A
- Cilia
- Flagella
- Microvilli
- Pseudopods
27
Q
Extracellular face of the plasma membrane
A
The side that faces outward
28
Q
Extracellular Fluid (ECF)
A
All body fluids not contained in the cells
29
Q
Facilitated Diffusion
A
- Carrier-mediated transport process of transporting a chemical through a cellular membrane
- Enables substances to diffuse through the membrane that would do so poorly, or not at all, without a carrier
- Down its concentration gradient
- Does not consume ATP
30
Q
Filtration
A
- A process in which hydrostatic pressure forces fluid through a selectively permeable membrane
- Notes
- Seen in the blood capillaries, where blood pressure forces fluid through gaps in the capillary wall
- This is how water, salts, nutrients, etc, are transferred from the bloodstream to the tissue fluid and how the kidneys filter wastes from the blood