Biomolecules, Cells, Tissues, Organ Systems, and Homeostasis - Vocabulary

Vocabulary flashcards covering key terms from biomolecules, cellular organization, tissues, organ systems, and homeostasis discussed in the lecture.

Lipids

A diverse group of nonpolar biomolecules (fats, phospholipids, cholesterol) used for energy storage, membrane structure, and steroid hormone synthesis.

Phospholipid

A lipid with a hydrophilic head and hydrophobic tails that forms the bilayer of cell membranes.

Cholesterol

A sterol used to make steroid hormones and other steroids; a building block for many lipids.

Steroid hormones

Hormones derived from cholesterol (e.g., testosterone, estrogen, progesterone, cortisone) that regulate various body functions.

Amino acids

Twenty different building blocks that string together in various sequences to form proteins.

Protein

Macromolecules that perform most body functions, provide structure, and enable movement; regulated by enzymes.

Enzymes

Proteins that speed up chemical reactions by lowering activation energy.

Nucleic acids

Biomolecules (DNA and RNA) made of nucleotides that store/transfer genetic information and guide protein synthesis.

Nucleotides

Monomer units that make up nucleic acids.

Chemical level of organization

Atoms and macromolecules (carbs, lipids, proteins, nucleic acids, water) forming the basis of life.

Cell

The basic living unit formed by biomolecules within a phospholipid membrane; chemicals alone are not alive.

Tissue

A group of cells that perform a common function.

Epithelial tissue

Tissue involved in protection, exchange, secretion, and/or absorption; can be single- or multi-layered.

Connective tissue

Tissue that supports, binds, and protects; e.g., bone, blood, and others.

Muscular tissue

Muscle tissue responsible for movement; includes skeletal, cardiac, and smooth muscle.

Nervous tissue

Tissue composed of neurons and supporting cells; enables signaling and control.

Organ

Two or more tissues organized to perform a specific function (e.g., stomach).

Organ system

Group of organs that work together to perform major bodily functions (humans have 11).

Six major functions

Protection, structure/movement, communication, transport, exchange, and reproduction.

Integumentary system

Skin; the main protective system that keeps the outside out and the inside in.

Homeostasis

Maintenance of internal balance (temperature, oxygen, nutrients, water, pH) via regulatory mechanisms.

Receptor

Sensor that detects a variable and reports its level to the control center.

Hypothalamus

Brain region that serves as the main control center for homeostasis; stores many set points.

Set point

The target value for a physiological variable in a regulatory system.

Effector

Muscle or gland that acts to restore homeostasis when a deviation is detected.

Negative feedback

Regulatory loop that returns a variable toward its set point; common in homeostasis.

Positive feedback

Amplifies deviation from the set point; typically short-lived (e.g., childbirth, lactation).

Edema

Accumulation of excess fluid in tissues causing swelling; indicates disruption in fluid balance.

Metabolism

All chemical reactions in the body, including catabolic (breakdown) and anabolic (build-up) processes.

Catabolic

Reactions that break down molecules to release energy.

Anabolic

Reactions that build larger molecules from smaller ones using energy.