Macromolecules
What type of chemical reaction breaks down macromolecules like polysaccharides or lipids into their constituent monomers by consuming a water molecule?
Hydrolysis
What is the primary role of cholesterol within the mammalian fluid mosaic membrane at normal body temperatures?
It stabilizes membrane fluidity (prevents it from becoming too fluid or too rigid).
As organisms become much larger, their volume grows exponentially faster than their outer boundary. What specific geometric ratio decreases, necessitating internal specialized gas exchange systems like lungs or gills?
Surface area to volume ratio
Which specific blood vessels contain walls that are exactly one endothelial cell thick to maximize the efficient diffuse-exchange of gases and nutrients with surrounding tissues?
Capillaries
While plants and sedentary animals are capable of localized mechanical movement, what is the specific biological term for the deliberate movement that results in the total displacement of an organism from one geographic location to another?
Locomotion
This element is a core component of nucleic acids and phospholipids but is completely absent from triglycerides and standard amino acids. What is it?
Phosphorus
If a specialized channel protein is required to move a specific polar molecule down its concentration gradient across a lipid bilayer, what type of transport is occurring?
Facilitated diffusion
What happens to hemoglobin when oxygen binds to it?
Conformation change (change in structure of the protein)
Before the ventricles contract, what valves are closed?
All valves would be closed to create the pressure needed to move the blood outside of the heart.
What is the fundamental, repeating structural and functional unit of a striated skeletal muscle cell, bounded on either end by Z-lines?
A sarcomere
While secondary protein structures are stabilized by hydrogen bonding along the polypeptide backbone, tertiary structures are stabilized by interactions between which specific molecular regions?
The R-groups (or side chains) of amino acids.
Animal cells lack cell walls. What catastrophic structural event will happen to a human red blood cell if it is placed into a highly hypotonic solution like distilled water?
Lysis (it will swell and burst)
When hard-working skeletal muscles produce high concentrations of carbon dioxide and lower the localized blood pH, hemoglobin responds by releasing its bound oxygen much more readily. What is the name of this rightward shift?
The Bohr Shift
This specific term describes the heart's unique mechanical ability to generate its own electrical impulses and contract automatically without requiring any nervous system stimulation.
Myogenic
During muscle relaxation, the binding sites on actin filaments are physically blocked by a regulatory protein complex. What specific ion must flood into the sarcoplasm to pull this blockage away?
Calcium ions
A molecule possesses both a highly hydrophilic, polar region and a distinct hydrophobic, non-polar region. What is the precise term used to describe this dual chemical nature?
Amphipathic
What specific cell membrane component consists of a localized carbohydrate chain attached to an integral protein and acts as a marker for cell-to-cell recognition?
Glycoprotein
In a clinical setting, a patient is suffering from severe emphysema, which destroys the delicate walls of the alveoli and fuses them into larger, fewer air sacs. In terms of physical principles, why does this drastically impair their rate of oxygen diffusion into the blood?
It significantly reduces the total surface area available for diffusion
On a standard electrocardiogram (ECG) trace, the large QRS complex wave indicates the electrical depolarization and subsequent contraction of which cardiac structures?
The ventricles
According to the sliding filament theory of muscle contraction, what happens to the absolute physical length of the individual thick myosin and thin actin protein filaments as a muscle shortens?
They remain exactly the same length (they slide past one another, they do not shorten)
Unlike fibrous proteins like collagen which serve structural roles, hemoglobin and myoglobin have intricate three-dimensional folds that make them water-soluble. What structural classification describes these spherical shapes?
Globular proteins
To prevent a plasma membrane from freezing solid and losing functionality in extreme cold environments, a cell will selectively alter its membrane composition by increasing the proportion of which type of fatty acid?
Unsaturated fatty acids
What is the physiological term for the standard volume of air that moves into and out of the human respiratory tract during a single, relaxed, normal breath?
Tidal volume
After the SA node fires and the wave of electrical depolarization stretches across the atria (seen as the P-wave on an ECG), what is the immediate mechanical response of the atria, and how does this affect atrial pressure?
The atria contract (atrial systole), which causes atrial pressure to rise above ventricular pressure, forcing the remaining blood through the AV valves.
During the cross-bridge cycle, what molecule must bind directly to the myosin head to cause it to detach from the actin filament, resetting the system for the next power stroke?
ATP