1_ Ch. 2,4 - Membrane Transport Flashcards
(87 cards)
1
Q
What is one characteristic that living things exhibit?
A
Organization
Living things maintain a higher level of organization and expend energy to maintain order.
2
Q
What happens to a living thing if it is unable to expend energy?
A
Loss of organization is accompanied by disease, death.
3
Q
What is the fundamental unit of cellular composition in living things?
A
Cells.
4
Q
How do cells interact with each other?
A
Cells are interdependent and work with each other.
5
Q
What are the two main processes involved in development?
A
Growth and Differentiation.
6
Q
What is metabolism?
A
The sum of all chemical reactions in a body or a cell.
7
Q
What are the two types of metabolic reactions?
A
- Anabolic
- Catabolic
8
Q
What is the primary role of hormones in metabolism?
A
Regulate metabolic processes.
9
Q
Define homeostasis.
A
Maintenance of relatively stable internal conditions.
10
Q
Give an example of homeostasis in action.
A
Maintaining body temperature despite cold external conditions.
11
Q
What is the significance of negative feedback in homeostasis?
A
It activates mechanisms that negate or reverse changes to maintain stability.
12
Q
What is a receptor in the context of feedback loops?
A
A structure that senses change.
13
Q
What is the integrating (control) center typically in feedback loops?
A
Usually the brain, specifically the hypothalamus.
14
Q
What is the effector in a feedback loop?
A
A structure that carries out the response.
15
Q
True or False: Positive feedback is the primary mechanism for maintaining homeostasis.
A
False.
16
Q
What is an example of a positive feedback mechanism in the body?
A
Blood clotting.
17
Q
What is the most abundant and important inorganic molecule in cells?
A
Water.
18
Q
What are the unique properties of water?
A
- Solvency
- Thermal stability
- Reactivity
- Cushioning
19
Q
What does the term ‘hydrophilic’ refer to?
A
Substances that dissolve in water and are usually polar.
20
Q
What is the role of carbohydrates in the body?
A
Energy source and structural components.
21
Q
What are the four major types of organic compounds?
A
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
22
Q
Fill in the blank: The study of molecules that compose living things is called _______.
A
Biochemistry.
23
Q
What is the primary function of lipids?
A
Energy storage and cell membrane structure.
24
Q
What are the three types of carbohydrates based on their structure?
A
- Monosaccharides
- Disaccharides
- Polysaccharides
25
What is hydrolysis?
A reaction where water is added to break bonds.
26
What is dehydration synthesis?
A reaction where water is removed to form bonds.
27
What is a Monosaccharide?
Only 1 ring: Glucose - blood sugar
## Footnote
Monosaccharides are the simplest form of carbohydrates.
28
What is a Disaccharide?
2 rings linked: Sucrose, Lactose
## Footnote
Disaccharides are formed from two monosaccharides.
29
Define Polysaccharides.
Long branching chains or polymers of linked monosaccharides
## Footnote
Polysaccharides serve various functions in the body.
30
What are Lipids?
Compounds composed of C, H & O (less O)
## Footnote
Lipids are hydrophobic and insoluble in water.
31
What are Triglycerides?
Fats (when solid) & oils (liquid) composed of fatty acids and glycerol
## Footnote
Triglycerides are the most efficient form of stored energy.
32
What is the ratio of Fatty Acids to Glycerol in Triglycerides?
3:1 ratio of Fatty Acids to Glycerol
## Footnote
This composition contributes to their energy storage capabilities.
33
What are Steroids?
Nonpolar, flat 4 ring structure, e.g., Cholesterol
## Footnote
Steroids are precursors to steroid hormones and other important molecules.
34
What is the main function of Phospholipids?
Main structural foundation of cell membranes
## Footnote
Phospholipids are amphiphilic, with polar heads and nonpolar tails.
35
What are Eicosanoids?
Diverse group of signaling molecules chiefly derived from 20C fatty acid: Arachidonic Acid
## Footnote
Eicosanoids include Prostaglandins, Thromboxanes, and play roles in inflammation.
36
What is the function of Prostaglandins?
Roles in blood clotting, regulating blood pressure, inflammation
## Footnote
Prostaglandins are important signaling molecules derived from arachidonic acid.
37
What are the two types of Proteins?
Fibrous (structural) and Globular (functional)
## Footnote
Fibrous proteins provide structure, while globular proteins perform various functions.
38
What is Protein Denaturation?
Drastic conformational change due to extreme heat or pH
## Footnote
Denaturation usually permanently destroys protein function.
39
What are the functions of Proteins?
* Structure
* Communication
* Membrane transport
* Catalysts (enzymes)
* Recognition & Protection
* Movement
* Cell adhesion
## Footnote
Proteins play diverse roles in biological systems.
40
What is the role of ATP?
Stores energy for physiological work
## Footnote
ATP is the primary energy currency in cells.
41
What is the structure of ATP?
Nitrogenous base = Adenine, Monosaccharide = Ribose, 3 Phosphate groups
## Footnote
High-energy phosphate bonds hold the negative oxygen atoms together.
42
Fill in the blank: ATP is converted to _______ + PO4 + energy.
ADP
## Footnote
This process releases energy for cellular activities.
43
What is the Citric Acid Cycle also known as?
Krebs cycle
## Footnote
This cycle is crucial for ATP production in mitochondria.
44
What are the three major categories of cellular functions of ATP?
* Transport of substances through membranes
* Synthesis of molecules
* Mechanical Work
## Footnote
ATP is essential for various cellular processes.
45
What is GTP?
Guanosine Triphosphate, another high energy nucleotide
## Footnote
GTP functions similarly to ATP but has less energy.
46
What is cAMP?
Cyclic adenosine monophosphate, a common second messenger
## Footnote
cAMP is involved in intracellular signal transduction.
47
What is the structure of cell membranes?
Lipid bilayer interspersed with globular proteins
## Footnote
This structure allows for selective permeability.
48
What do Glycolipids do?
Function in signaling, identification of the cell
## Footnote
Glycolipids have sugar groups extending only on the outer plasma membrane surface.
49
Differentiate between Integral and Peripheral proteins.
* Integral proteins: Pass through the entire membrane
* Peripheral proteins: Not embedded, attach loosely
## Footnote
Integral proteins often function in transport, while peripheral proteins may serve as enzymes.
50
What is the Glycocalyx?
Fuzzy, sticky coating of cells that surrounds the entire portion of the cell
## Footnote
It contributes to cell recognition and protection.
51
What are the two types of Diffusion?
* Simple diffusion
* Facilitated diffusion
## Footnote
Both types occur without the use of ATP.
52
What is Passive Transport?
Movement of molecules down their concentration gradient
## Footnote
This process does not require energy.
53
What is required for molecules to diffuse through the membrane?
* Concentration gradient
* Lipid-soluble
* Small enough to fit through channels
## Footnote
These factors facilitate the diffusion process.
54
What are the two types of diffusion through the membrane?
* Simple diffusion
* Facilitated diffusion
## Footnote
Simple diffusion involves unassisted movement across the lipid bilayer, while facilitated diffusion requires a carrier protein.
55
Define simple diffusion.
Unassisted diffusion of lipid-soluble or very small particles across the membrane
## Footnote
This process occurs without the use of a carrier protein.
56
What factors affect the rate of diffusion?
* Lipid solubility
* Number of protein channels
* Temperature
* Molecular weight of diffusing substance
* Thickness of membrane
* Concentration difference
* Charge gradient
## Footnote
Each of these factors can accelerate or decelerate the movement of substances across the membrane.
57
What are protein channels?
Integral membrane proteins that form open tubes for transporting substances
## Footnote
These channels are selective based on pore size and the charges of amino acids lining the channel.
58
What is the difference between voltage-gated, ligand-gated, and mechanical-gated channels?
* Voltage-gated: respond to electrical potential changes
* Ligand-gated: respond to specific molecules binding
* Mechanical-gated: respond to physical stress on the cell
## Footnote
Each type of gated channel opens in response to different stimuli.
59
What is osmosis?
Diffusion of water across a semipermeable membrane
## Footnote
Water moves from areas of high water concentration to areas of low water concentration.
60
What is the significance of osmotic pressure?
The amount of pressure required to stop osmosis
## Footnote
It indicates how much pressure must be applied to prevent water movement across a membrane.
61
Define hypertonic and hypotonic solutions.
* Hypertonic: solution has more solutes than the cell
* Hypotonic: solution has fewer solutes than the cell
## Footnote
These terms describe the relative concentrations of solutes inside and outside the cell.
62
What is the difference between primary and secondary active transport?
* Primary active transport: energy from ATP hydrolysis
* Secondary active transport: energy from ionic gradients created by primary transport
## Footnote
Primary transport directly uses ATP, while secondary transport indirectly relies on ATP-generated gradients.
63
What is facilitated diffusion?
Movement of substances across the membrane via a carrier protein without ATP
## Footnote
This process occurs when substances are polar or too large to fit through channels.
64
What is the role of solute pumps in active transport?
Move substances against their concentration gradient using ATP
## Footnote
These pumps are specific for various ions and molecules.
65
What are the three types of endocytosis?
* Phagocytosis
* Pinocytosis
* Receptor-mediated endocytosis
## Footnote
Each type involves the uptake of different substances into the cell.
66
What is osmolarity?
Total concentration of all solute particles in a solution
## Footnote
It determines the extent to which water moves across a membrane.
67
What is the importance of isotonic solutions?
Have solute concentrations equal to ICF, resulting in no net movement of water
## Footnote
Isotonic solutions are crucial for maintaining cell shape and function.
68
What happens when a cell is placed in a hypertonic solution?
Water moves out of the cell, causing it to shrink
## Footnote
This occurs because the external solution has a higher solute concentration.
69
What is the function of aquaporins?
Permit passage of water while excluding other substances
## Footnote
Aquaporins are integral membrane proteins abundant in RBCs and kidney tubules.
70
Fill in the blank: The concentration gradient created by the Na-K pump is essential for _______.
[secondary active transport]
## Footnote
This gradient allows other substances to be transported into the cell.
71
True or False: Active transport requires ATP.
True
## Footnote
Active transport mechanisms move substances against their concentration gradients, necessitating energy.
72
What is exocytosis?
Vesicle fuses with the membrane and ejects its contents into the outside of the cell
## Footnote
This process is essential for the release of neurotransmitters and hormones.
73
What is endocytosis?
Vesicle formed from the cell membrane that brings contents from the extracellular fluid into the cell
## Footnote
Includes three types: phagocytosis, pinocytosis, and receptor-mediated endocytosis.
74
Define phagocytosis.
Cell eating, where white blood cells consume bacteria
## Footnote
Involves large particles like dead cell fragments and antigens.
75
What is pinocytosis?
Cell drinking, where small substances like electrolytes and amino acids are engulfed
## Footnote
This process is non-specific and does not involve receptors.
76
What is receptor-mediated endocytosis?
Specific endocytosis where receptors bind to ligands and pull them into the cell
## Footnote
Once occupied, the vesicle pinches off and may release ligands inside or fuse with lysosomes.
77
What is the most famous solute pump?
The Sodium-Potassium pump
## Footnote
It plays a critical role in maintaining the gradient of sodium and potassium ions across the cell membrane.
78
What enzyme is responsible for the Sodium-Potassium pump?
Na+ - K+ ATPase
## Footnote
This enzyme is crucial for the active transport of sodium and potassium ions.
79
What are the typical concentrations of potassium inside and outside the cell?
Inside: 140 mEq/L, Outside: 4 mEq/L
## Footnote
These concentrations are vital for cellular function and membrane potential.
80
What are the typical concentrations of sodium inside and outside the cell?
Inside: 10 mEq/L, Outside: 142 mEq/L
## Footnote
Maintaining this gradient is essential for various cellular processes.
81
How does the Sodium-Potassium pump function?
Exchanges 3 Na+ for 2 K+
## Footnote
It binds sodium ions from the intracellular fluid and transports them out, while bringing potassium ions into the cell.
82
What is the significance of the concentration gradients maintained by the Na-K pump?
Essential for proper fluid volume and membrane potential in all cells
## Footnote
About half the calories burned each day fuel this pump.
83
What is the role of active transport of calcium?
Pumps calcium out of almost all body cells
## Footnote
Calcium is generally non-existent inside cells and is stored in extracellular fluid and intracellular vesicles.
84
Where does active transport of hydrogen occur?
In gastric glands and kidneys
## Footnote
This process helps maintain acid-base balance.
85
What type of transporter is the Na-K pump?
Coupled transporter
## Footnote
It moves more than one substance at a time.
86
What is a symport pump?
A transporter that moves solutes in the same direction
## Footnote
An example includes certain glucose transporters.
87
What is an antiport pump?
A transporter that moves solutes in opposite directions
## Footnote
The Na-K pump is an example of an antiport pump.
