Chemistry and Enzymes
What type of chemical bond involves unequal sharing of electrons, creating partial charges like in water molecules?
Polar Covalent Bond
What happens to a red blood cell placed in a hypotonic solution?
Where in the cell does glycolysis take place, and what is its net ATP yield per glucose?
Cytoplasm; Net yield of 2 ATP
What is the typical resting membrane potential of a neuron, and which side is negative?
-70 mV; Inside of the cell is negative
What are the two anatomical divisions of the Nervous System?
Central Nervous System (CNS) & Peripheral Nervous System (PNS)
How do enzymes speed up chemical reactions without being consumed in the process?
By lowering the Activation Energy barrier
What ions and quantities are moved by the primary active transport Na+/K+ ATPase pump
3 Na+ OUT of the cell, 2 K+ INTO the cell
What is the crucial role of Oxygen in aerobic cellular respiration?
Final Electron Acceptor at the end of the ETC
What are the equilibrium potentials for K+ and Na+?
EK = -90 mV | ENa = +66 mV
Which division of the Autonomic Nervous System mediates 'Fight or Flight' responses?
Sympathetic Nervous System
Salivary amylase works optimally in the mouth at a pH of 7. What happens to its 3D structure and function when it is swallowed into the acidic stomach (pH 2)?
It denatures and loses function
How does secondary active transport (e.g., Na+/glucose cotransport) power glucose movement?
Using energy from Na+ diffusing down its gradient
How does ATP Synthase generate ATP during oxidative phosphorylation?
H+ ions (protons) diffuse down gradient through ATP Synthase
Which ion movement causes the rapid Depolarization phase of an action potential?
Na+ rushing INTO the cell through voltage-gated Na+ channels
Which neurons are responsibly for carrying motor signals away from the CNS?
Efferent neurons.
In a branching metabolic pathway, how does end-product inhibition regulate product levels?
Final product allosterically inhibits an earlier enzyme
Why does carrier-mediated transport reach a maximum rate (saturation) while simple diffusion does not?
All carrier transport proteins become occupied
Why must Pyruvate be converted to Lactate during anaerobic exercise?
To regenerate NAD+ from NADH
What causes the Absolute Refractory Period during an action potential?
Inactivation gates of voltage-gated Na+ channels are closed
Voltage-gated Na+ channels have two distinct gates: an activation gate and an inactivation gate12. What triggers the activation gate to open?
Threshold depolarization (approx. -55 mV) opens the activation gate
In the inborn error of metabolism Phenylketonuria (PKU), why does disease occur?
Lack of enzyme one causes phenylalanine buildup and toxicity
What type of transport mechanism would a cell use to secrete insulin or neurotransmitters in large quantities?
Exocytosis (Bulk Vesicle Transport)
In the Cori Cycle, how do the skeletal muscle and liver collaborate during intense recovery?
Muscle sends Lactate to Liver; Liver converts it to Glucose
How do Graded Potentials differ from Action Potentials in location and magnitude?
Graded: Dendrites/soma, variable size, decay. Action: Axon, all-or-none, constant size
What ion channel behavior causes the Relative Refractory Period?
Voltage-gated K+ channels are slow to close, causing hyperpolarization (membrane potential drops below -70 mV toward EK = -90 mV)