Biology Chapter 5 Quiz

Introduction to Human Physiology: Cell Components and Organelles

• Human physiology is the study of the functional activities and mechanisms within the biological body. Examples include the heartbeat's automatic function.
• Physiological processes are derived from the Greek words physis (nature) and logos (study).
• The human body is organized from atoms, to molecules, macromolecules, organelles, tissues, organs, organ systems, and finally the organism.
• Cells are the fundamental units of all living organisms, including bacteria, protozoans, fungi, plants, and animals.
• Humans are multicellular organisms, composed of trillions of cells.
• Every living organism has cells.
• Human cells require basic needs like oxygen, food, and waste removal.
• About 200 specialized cells work together for homeostasis.

Levels of Organization

• Atoms (e.g., hydrogen, carbon) form the base of the body's organization.
• Molecules (e.g., water, glucose) follow atoms.
• Macromolecules (e.g., proteins, DNA) then follow molecules.
• Organelles (e.g., nucleus, mitochondria) are found within cells.
• Tissues (e.g., bone, muscle) are collections of similar cells.
• Organs (e.g., heart, kidneys) are formed from different tissues.
• Organ systems (e.g., skeletal, cardiovascular) are integrated organs.
• Organisms (animals, plants, bacteria, fungi) are the highest level of organization.

Characteristics of Life

• Reproduction (micro and macro) is essential for maintaining and increasing efficient growth.
• Growth is needed for proper development.
• Movement allows for seeking nutrition, mates, and escaping predators.
• Respiration obtains oxygen, and releases carbon dioxide.
• Responsiveness allows for adaptation to environmental changes.
• Digestion breaks down food for energy.
• Absorption moves substances into body fluids.
• Circulation involves transporting substances in body fluids.
• Assimilation changes absorbed substances into usable forms for the body's tissues.
• Excretion removes waste products.

Introduction to Cell Biology

• Cells are the fundamental units of all living things.
• Some organisms are unicellular (e.g., bacteria, protozoans).
• Humans, like other animals, are multicellular.
• Adult humans are composed of about 100 trillion cells.

Parts of the Human Cell

• The cell has a plasma membrane, cytoplasm, and nucleus as three main parts.
• The cell membrane separates the interior from the outside environment while allowing substances in and out of the cell.
• Organelles, like the nucleus, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria, and cytoskeleton, are complex components within the cell, performing specific functions.

Endoplasmic Reticulum

• Rough ER (with ribosomes) synthesizes and modifies proteins.
• Smooth ER synthesizes lipids and detoxifies substances.

Cytoplasm

• The cytoplasm is the fluid portion within the plasma membrane and contains organelles surrounded by cytosol, which includes water, dissolved substances, and particles.
• The cytoskeleton is a framework for organelles and macromolecules.

Golgi Apparatus

• The Golgi apparatus is a stack of vesicles related with the ER.
• It modifies, sorts, and packages proteins to be used inside of the cell or secreted outside the cell.

Lysosomes

• Lysosomes are vesicles containing enzymes that break down waste materials inside of the cell.

Peroxisomes

• Peroxisomes contain enzymes that prevent toxic substances in the cells using hydrogen peroxide.

Mitochondria

• Mitochondria are involved in energy production.
• They have an inner and outer membrane.
• ATP (adenosine triphosphate) is a high-energy compound produced in mitochondria.

Cytoskeleton

• The cytoskeleton provides internal structure and support.
• Microtubules, microfilaments, and intermediate filaments are the main components.
• They are important in moving organelles and macromolecules in the cell.

Cilia and Flagella

• Cilia and flagella move materials across the cell surface or propel the cell.

Microvilli

• Microvilli increase the surface area for rapid diffusion.

Transport in the Cell Membrane

• Endocytosis includes phagocytosis ("cell eating") which engulfs large particles, and pinocytosis("cell drinking") for absorbing small amounts of extracellular fluid.
• Exocytosis releases materials from the cell

Cell functions vary based on cell type and location

• Organelles work together to maintain life functions.
• Specialized organelles are related to particular functions.
• The cell's needs for energy and nutrients, replication, contribute to the overall function.