Comprehensive Study Guide to Life Functions, Cytology, Homeostasis, and Biochemistry

Vocabulary practice flashcards covering cell organization, organelle functions, membrane transport, homeostasis, feedback mechanisms, and biochemistry concepts from the Life Functions study guide.

Biological Organization

The hierarchy of biological structures ordered from simplest to most complex: organelle, cell, tissue, organ, organ system, and organism.

Eukaryotic Cells

Cells that contain membrane-bound organelles and have genetic material contained in a nucleus; includes Animalia and Fungi.

Prokaryotic Cells

Cells that lack membrane-bound organelles and lack a defined nucleus; includes Bacteria and Archaea/Archaeabacteria.

Characteristics of Living Things

The five defining features of life: living things are organized, respond to stimuli, use energy, grow and develop, and reproduce.

Metabolic Processes

Chemical processes essential for life; an object's inability to perform them leads to the conclusion that it is non-living.

Viruses

Exceptions to the cell theory that nonetheless possess certain characteristics of living things, such as containing genetic material.

Nucleus

A membrane-bound organelle that stores genetic material.

Mitochondria

Cellular organelles responsible for creating energy.

Chloroplast

The organelle in plant cells that serves as the site of photosynthesis.

Ribosomes

Structures within the cell that create proteins.

Golgi Body

The packaging center of the cell.

Lysosome

An organelle that destroys cellular waste products.

Rough Endoplasmic Reticulum

An organelle that creates and edits proteins.

Cell Membrane

A selectively permeable boundary that controls what enters or exits the cell.

Selectively Permeable

A property of a membrane allowing only specific molecules to pass through depending on their size, shape, and type.

Protein Channels

Membrane proteins used by molecules that are too large to move across the cell membrane on their own.

Contractile Vacuole

A structure in single-celled pond organisms that maintains water balance by pumping excess water out, functioning analogously to the human kidney.

Homeostasis

An optimal range in which the body can function, rather than a fixed set point.

Negative Feedback Loop

A biological feedback mechanism in which the effect of the body's response counters the stimulus to restore homeostatic range (e.g., blood sugar regulation, sweating, shivering).

Positive Feedback Loop

A biological feedback mechanism in which the effect of the body's response encourages or amplifies the stimulus (e.g., childbirth, sneezing, allergic reactions, blood clotting).

Insulin

A hormone secreted by the pancreas when blood sugar increases that lowers blood sugar levels back to homeostatic range by storing sugar in the liver.

Histamines

Chemicals released by nasal cells in response to foreign particles that cause irritation and trigger a positive feedback loop until sneezing ends their release.

Evaporative Cooling

A cooling mechanism where sweating decreases body temperature if it gets too high during intense exercise.

Red Blood Cells and Aquaporins

Cells containing hemoglobin for oxygen transport that use aquaporin water channels to absorb and release water as needed to maintain homeostasis.

Carbohydrates

Macromolecules composed of simple sugars (monosaccharides) that provide short-term energy and structural support in plants.

Proteins

Macromolecules composed of amino acid monomers that function as enzymes, hormones, and various cellular structures.

Lipids

Macromolecules composed of fatty acid monomers that function in long-term energy storage and insulation.

Nucleic Acids

Macromolecules composed of nucleotide monomers that store and transmit genetic information.

Enzymes

Biological catalysts that speed up metabolic chemical reactions within organisms by decreasing the activation energy required for the reaction.

Active Site

The specific region of an enzyme that matches the shape of its substrate, ensuring the proper enzyme only performs a specific desired function.

Denaturation

The process by which an enzyme loses its shape due to an increase in temperature or a change in pH, altering the active site so it can no longer interact with the substrate.

Gastric Protease

A digestive enzyme that operates at an optimal pH of around $3$.