CHAPTER 3: CELL ANATOMY Flashcards
Specialized structures in cells that perform specific functions.
Example: nucleus, mitochondria, ribosomes
Organelles
Jelly-like substance that holds organelles.
Cytoplasm
Also termed the plasma membrane. It is a structure that encloses the cytoplasm.
Cell membrane
What are the functions of the cell?
• Smallest units of life
• Cell metabolism and energy use
• Synthesis of molecules
• Communication
• Reproduction and inheritance
Is the outermost component of the cell. It forms a boundary between material inside the cell and outside. It acts as a selective barrier.
Cell membrane
Materials inside the cell are called what?
Intracellular
Materials outside the cell are called what?
Extracellular
The fluid inside the cell is called _______
Intracellular Fluid (ICF)
The fluid outside the cell is called ________.
Extracellular fluid (ECF)
What is the model used to describe the cell membrane structure?
Fluid-mosaic model
Add: It is proposed by Singer-Nicolson.
The cell membrane of the cell contains ________, _______, ________, and ________.
Phospholipid, cholesterol, proteins, and carbohydrates
The cell membrane of the cell forms phospholipid bilayer and it contain 2 regions. What are these?
Polar region - This part is the head which is hydrophilic - loves water
Nonpolar region - This part is the tail which is hydrophobic - fear water
Note: This phospholipid bilayer is passive (doesn’t use energy)
A phospholipid molecule has a polar head region that is _________ and a nonpolar tail region that is _________.
Hydrophilic
Hydrophobic
The _______ region of the phospholipid is exposed to water around the membrane.
Polar
The ______ region of the phospholipid is facing the interior of the membrane.
Nonpolar
The cell membrane has ____________, which allows only certain substances to pass in and out of the cell.
Selective permeability
Substances such as _______, ________, and ________ are found in higher concentrations inside the cell.
Enzymes, glycogen, and potassium
Substances such as ________, ________, and ________ are found in higher concentrations outside the cell.
Sodium, calcium, and chloride
PISO in cell membrane means
Note: This is only a technique from our professor for us to remember this part in cell.
Potassium INSIDE Sodium OUTSIDE
Some substances, like _____ and _____, can pass directly through the cell membrane’s phospholipid bilayer
Oxygen (O2) and Carbon Dioxide (CO2)
Some substances must pass through transmembrane protein channels, such as _____ through its channels.
Sodium (Na+)
The route of transport through the membrane depends in the _____,_____, and ______ of the substance.
Size, shape, and charge
Some substances require carrier molecules to transport them across the cell membrane, such as _______.
Glucose
Some substances require a ________ across the cell membrane. The vesicle must fuse with the cell membrane for transport.
Vesicular transport
What are the 2 membrane transport?
Active and Passive transport
What membrane transport does not require the cell to expend energy?
Example: CO2, O2, Steroids, Lipid, fats soluble vitamins (A, D, E, and K)
Passive Transport
Note: This is because the molecules move from higher concentration to low concentrated area.
What membrane transport does require the cell to expend energy, usually in the form of ATP?
It needs molecule or protein channel.
Example: Sodium, potassium
Active Transport
Note: This is because the molecules move from low concentration to high concentration.
Passive membrane transport mechanism include ________, _______, and _________.
Diffusion, Osmosis, and Facilitated Diffusion
Active membrane transport mechanisms include __________, _________, ________, and _________.
- Active transport
- Secondary active transport
- Endocytosis
- Exocytosis
This is the type of passive transport where there is movement of molecules down their concentration gradient from an area of higher concentration to an area of lower concentration.
Diffusion
A solution is generally composed of two major parts. What are these?
Solutes and solvent
Solutes are substances dissolved in a predominant liquid or gas, which is called what?
Solvent
This is the difference in the concentration of a solute in a solvent between two points divided by the distance between the two points.
Concentration gradient
The concentration gradient is said to be ________ when the concentration difference is large and/or the distance is small.
Steeper
Determine the sequence of diffusion:
A. Salt ions (green) move down their concentration gradient into the water.
B. When a salt crystal (green) is placed into a beaker of water, a concentration gradient exists between the salt from the salt crystal and the water that surrounds it.
C. Salt ions and water molecules are distributed evenly throughout the solution. Even though the salt ions and water molecules continue to move randomly, an equilibrium exists, and no net movement occurs because no concentration gradient exists.
B, A, C
Involves the movement of molecules across the membrane but with the aid of either channel or carrier proteins. These molecules are usually those that cannot cross due to their molecular size or chemical nature.
Facilitated diffusion
_______ soluble substances can diffuse directly through the phospholipid bilayer.
Lipid
Water-soluble substances, such as ions, can diffuse across the cell membrane only by passing through what?
Cell membrane channels
What are the two classes of cell membrane channels?
Leak channels and Gated channels
This is one of the two classes of cell membrane channels that constantly allow ions to pass through.
Leak channels
Class of cell membrane channels that limits the movement of ions across the membrane by opening and closing.
Gated channels
Is the diffusion of water (a solvent) across a selectively permeable membrane from a region of higher water concentration to one of lower water concentration.
Osmosis
Three requirements for osmosis to happen:
- Solvent - water
- Selectively permeable membrane (SPM)
- Higher to lower concentration
Osmosis exerts a pressure, a termed __________, which is the force required to prevent movement of water across cell membrane.
Osmotic pressure
Osmotic pressure depends on the difference of ___________ inside a cell relative to outside the cell.
Solution concentration
What solution has a lower concentration of solutes and a higher concentration of water relative to the cytoplasm of the cell. The water goes inside the cell
The solution has less tone, or osmotic pressure, than the cell.
Hypotonic
Note: Water is attracted to salt, that’s the reason why the water goes inside the cell since there is higher concentration of solute inside.
In hypotonic, water moves by osmosis into the cell, causing it to swell.
If the cell swells enough, it can rupture, a process called _________
Lysis
This solution has the same solute concentrations inside and outside the cell. The cell will neither shrink nor swell. No movement of water.
Isotonic
Note: Iso means equal
The cytoplasm of the cell in this solution has a lower solute concentration and higher water concentration than the surrounding solution. The water goes outside the cell.
Hypertonic solution
Water moves by osmosis from the cell into the hypertonic solution, resulting in what?
Cell shrinkage or crenation
In carrier-mediated transport
Some water-soluble, electrically charged or large sized particles cannot enter or leave through the cell membrane by diffusion. These substances include _______, ______, and some __________ produced by the cell.
Amino acids, glucose, some polar molecules
These are proteins within the cell membrane involved in carrier-mediated transport.
Carrier molecules
Carrier-mediated transport mechanisms includes these two. What are these?
Facilitated diffusion and Active transport
Note:
Facilitated diffusion does not require ATP for energy while Active transport does require ATP for transport.
Is a carrier-mediated transport process that moves substances across the cell membrane from an area of higher concentration to an area of lower concentration of that substance.
Facilitated diffusion
In facilitated diffusion,
Because the movement is with the concentration gradient, metabolic energy in the form of ATP is ________
A. required
B. not required
B. not required
Is a carrier- mediated process, requiring ATP, that moves substances across the cell membrane from regions of lower concentration to those of higher concentration against a concentration gradient.
Active transport
_____________ processes accumulate necessary substances on one side of the cell membrane at concentrations many times greater than those on the other side.
Active transport
A major example of active transport is the action of the _________ present in cell membranes. This moves Na+ out of cells and K+ into cells.
The result is a higher concentration of Na+ outside cells and a higher concentration of K+ inside cells.
Sodium-Potassium Pump
Uses the energy provided by a concentration gradient established by the active transport of one substance, such as Na+ to transport other substances.
No additional energy is required above the energy provided by the initial active transport pump.
Secondary active transport