BIO NMDCAT

Facilitated diffusion uses transmembrane proteins to move molecules that cannot pass through the lipid bilayer directly.

Peripheral proteins are loosely attached to the surface, usually via non-covalent interactions like ionic or hydrogen bonds.

Shorter chains decrease van der Waals interactions, and double bonds create fluidity; this combination results in the highest fluidity.

Glycolipids act as markers for cell identification and adhesion in the extracellular matrix.

Freeze-fracture techniques show proteins distributed within the bilayer, confirming the mosaic nature.

According to Fick's law, the rate of diffusion is directly proportional to the steepness of the concentration gradient.

The cerebellum continuously coordinates skeletal muscle activity and balance, allowing smooth movements with minimal conscious control.

The respiratory centers in the medulla oblongata automatically regulate breathing throughout life, including during sleep and unconsciousness. The cerebral cortex can voluntarily modify breathing but is not required for its continuous maintenance.

Most motor nerve fibers decussate (cross) in the medulla oblongata. Consequently, the left cerebral hemisphere controls the right side of the body, and the right hemisphere controls the left side.

The cerebellum continuously receives information from muscles, joints, and the inner ear to coordinate posture, muscle tone, and balance. Damage to it results in poor balance and uncoordinated movements.

The pons connects different regions of the brain, particularly the cerebrum and cerebellum, and contains respiratory centers that help regulate the depth and rhythm of breathing.

The cerebrum plans and initiates voluntary movements, while the cerebellum coordinates their timing, precision, and balance. Without cerebellar input, movements become irregular and poorly coordinated.

The hypothalamus is the principal homeostatic center of the brain. It regulates body temperature, hunger, thirst, water balance, sleep, and endocrine functions through its influence on the pituitary gland. Intelligence is a function of the cerebrum, vision and hearing involve the cerebral cortex and midbrain, while voluntary muscle contraction is initiated by the motor cortex.

The midbrain contains centers responsible for visual and auditory reflexes, such as turning the eyes or head toward a stimulus. Temperature regulation is performed by the hypothalamus, sensory relay by the thalamus, and memory mainly involves the cerebrum.

The cerebellum coordinates voluntary muscle movements, balance, posture, and muscle tone. The cerebrum initiates voluntary movement, but the cerebellum ensures accuracy and smooth execution.

The brain stem serves as the main conduction pathway connecting the brain with the spinal cord while also housing vital autonomic centers.

The medulla controls respiration, heartbeat, and blood pressure. Severe damage can immediately threaten life, whereas cerebral injury mainly affects higher mental functions.

The folds (gyri and sulci) greatly increase the cortical surface area, allowing more neurons to be accommodated for complex mental functions.

The hypothalamus functions as the body's thermostat and activates mechanisms such as sweating and vasodilation to reduce body temperature.