The Nerntz potential for Na+ does not suggest that the concentration of this ion is equal on both sides of the membrane.
The movement of water across a membrane is always an active process requiring primary active transport.
The Nernst Equation is important for:
Determining the absolute membrane potential.
Determining the electrical potential difference, for a single ion, needed to counter the concentration difference.
Determining the electrical potential difference, for multiple ions, needed to counter the concentration difference.
Determining the concentration difference, for multiple, needed to counter the electrical potential difference.
When determining the "equilibrium potential" for Na+, we have to assume the membrane is permeable to all solutes.
Any difference in energy across a membrane is considered the ___________ that pushes a molecule in one direction of the other.
To initiate the action potential of the cell's resting membrane potential must first be changed to reach the threshold of voltage-gates sodium channels.
Which process listed below is most responsible for maintaining the electrochemical gradient of a resting membrane?
facilitated diffusion of Na+
If a positively charged ion is more concentrated inside the cell, the electrical forces required to balance the chemical gradient would be directed ____________. Thus, the equilibrium potential (which reflects the voltage inside of the cell) for this ion would be __________ charged.
Extracellular Na+ is higher than intracellular Na+. If the membrane potential were allowed to reach the equilibrium potential for Na+, in which direction (at the moment equilibrium is reached) would overall Na+ movement be?
no net movement
varies by cell
The initial rapid change in resting membrane voltage (potential) seen during an action potential is called the "repolarization phase".
The functioning (physiology) of our body is dependent and mimics the functioning of _____________.
all of the above
The largest concentration of the body’s water resides in the ____________________.
Na+ has a higher concentration in the extracellular fluid, than in the intracellular fluid.
In warm weather, particular sensors within the body may sense that the body temperature is increasing. In response the systems of the body respond by trying to decrease the temperature change. This is an example of________________________.
Starbuck’s coffee reaction
Osmotic control, moving water from inside the body out
Homeostasic control systems
I don’t know
Lactose is a disaccharide composed of ...
Glucose and Lactose
Galactose and Glucose
Galactose and Fructose
Fructose and Glucose
Which statement about enzymes is not true?
Enzymes are generally proteins
For enzymes to be active they should first bind/link to a reactant molecule (substrate)
Are usually one dimensional in shape and function.
Can catalyze a reaction between to other molecules.
The enzyme _______ catalyzes the reaction whereby nucleotides are added to the polynucleotide chain that contains DNA (deoxyribose sugars).
The Mitochondria –
Can vary in number from cell to cell
Utilizes Aerobic mechanisms (electron transport chain) to produce ATP
Uses phospholipids for its membrane
All of the above
The Golgi apparatus sorts, modifies and packages proteins into vesicles targeted for their final destination.
The property of phospholipids can be described as ___________.
A single polar region that is miscible in aqueous solution.
A hydrophobic region that associates with water and hydrophilic regions that face one another.
A hydrophilic region that associates with water and hydrophobic regions that face one another.
None of the above
Which statement is NOT an accurate description of HOMEOSTATIC mechanisms of the body?
They function through either positive or negative feedback systems.
They maintain each regulated variable around a set point.
They maintain a constant internal environment in the face of a variable external environment.
They have an unlimited capacity to respond to changes in the external environment.
The _________________ is the site where lipids, triglycerides, and steroids are synthesized, as well as where calcium is stored within the cell.
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
The enzymes of glycolysis are located within the ______________ of the cell.
inner mitochondrial membrane
outer cell membrane
The concentration of Na+ in mammalian systems is generally
Lower outside of the cell versus inside of the cell.
Higher outside of the cell versus inside of the cell.
Equal on both sides of the cell membrane
Not an issue due to the ions permeability of the membrane.
The rate of diffusion in an open solution is dependent on several factors including concentration gradient, permeability across the membrane, viscosity of the fluid, and temperature.
Which choice below does not play a role in determining osmolarity?
Concentration of solute
Solutes that can cross the membrane
Solutes that can not cross the membrane
Active transport differs from facilitated diffusion in that it uses energy to move a substance (downhill) in the direction of its concentration or electrical gradient.
Passive transport of an ion requires that it move down its concentration gradient.
Properties associated with protein membrane active transporters is/are -
Uses energy from solute concentration gradient
Uses energy stored in ATP bonds
Which statement below is true?
Voltage across a membrane is “pressure”.
A Concentration differences across a membrane is a “pressure”.
The cell membrane containing a cell can be considered a “pressure”
All of the above are true
Osmotic pressure is the pressure necessary to prevent the movement of water across a membrane.
Sodium-linked glucose transport, where both Na+ and glucose are moving in the same direction, is an example of
Secondary active transport.
Primary active transport.
The Na+/K+ pump is an excellent example of secondary active transport.
Extracellular Na+ is higher than intracellular Na+. If the voltage across the membrane of the cell were to reach the
equilibrium potential for Na+, at the moment it reaches equilibrium, in which direction would the net Na+ movement be?
No net movement of Na+