Biology Chapter on Cell Structure and Functions

The study of the structure of living organisms.

The basic unit of structure and function for all living organisms.

The principle that all living things are composed of cells, and all cells come from pre-existing cells.

The sum of all chemical processes that occur within a living organism, including the breakdown of nutrients and the synthesis of new molecules.

The maintenance of a stable internal environment within an organism, despite changes in the external environment.

Fluid loss exceeds intake, lowering intracellular and extracellular fluid levels. Common sources are vomiting, diarrhea, and excessive sweating. This can lead to metabolic problems and even death in infants due to their small fluid volume.

Inorganic compounds without carbon that form ions in water. Ions conduct electricity. They are important for water movement, pH control, nerve and muscle function, and enzyme activity. Acids, bases, and salts are types of electrolytes. Low levels can cause muscle cramps, heart attacks, and brittle bones.

Nitrogen-containing organic compounds. Organic compounds are made up of carbon, hydrogen, and oxygen. Amino acids are the building blocks of proteins. They comprise an amino group (-NH2) and a carboxyl group (-COOH). There are 20+ different amino acids. Proteins are responsible for structural support and metabolic function.

Organic molecules with a 2:1 ratio of hydrogen to oxygen. They include monosaccharides (single sugars), disaccharides (two sugars linked), and polysaccharides (long chains of sugars). They are the primary energy source and fuel reserve. Excess carbohydrates are stored as fat or glycogen (stored glucose).

Include fats and fat-related substances, such as cholesterol. Primarily composed of long chains of carbon atoms. Their functions include building cell membranes, supplying energy, synthesizing hormones, and providing insulation. They are insoluble in water.

The outermost boundary of a cell, responsible for regulating what enters and exits the cell. It acts as a selective barrier, allowing only specific substances to pass through.

The scientific name for the plasma membrane, emphasizing its lipid bilayer structure. It's crucial for maintaining the cell's integrity and facilitating communication with its surroundings.

The structural arrangement of the plasma membrane, composed of two layers of lipid molecules. This bilayer creates a barrier that is selectively permeable, allowing only certain molecules to pass through.

A term used to describe the structure of the plasma membrane under an electron microscope. It appears as three layers (trilaminar) due to the arrangement of the lipid bilayer.

This model describes the plasma membrane as a dynamic structure, with a fluid lipid bilayer containing various proteins embedded within it. The proteins move freely within the membrane, contributing to its fluidity.

The ability of the plasma membrane to allow only certain substances to pass through, while blocking others. This selectivity is crucial for maintaining the cell's internal environment.

The movement of molecules from an area of high concentration to an area of low concentration, driven by the concentration gradient. This process is essential for transporting substances across the plasma membrane.

The movement of water across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. This process helps regulate the cell's water content and maintain its internal environment.

The cell's largest membrane-bound structure. It houses DNA, directs cellular processes, and contains the nucleolus.

A dense region within the nucleus where ribosome subunits are assembled. It contains parts of several chromosomes.

The selectively permeable membrane surrounding the nucleus. It contains pores that connect the nucleus to the cytosol.

A fluid-filled region between the nucleus and the cell membrane. It contains the cytosol and various organelles.

A network of protein fibers that provides structural support, anchors organelles, and assists in transporting molecules within the cytoplasm.

Powerhouses of the cell. They are responsible for producing energy in the form of ATP.

The outer membrane of a mitochondrion. It is smooth and involved in lipid synthesis and fatty acid metabolism.

The inner membrane of a mitochondrion. It is folded into cristae and involved in ATP production.

The inner compartment of the mitochondria, containing enzymes for ATP production and various metabolic pathways. It also holds carnitine, which helps transport fatty acids for energy conversion.

A process where mitochondria in an embryo are solely inherited from the mother's egg cell.

A condition where an individual has a mixture of normal and abnormal mitochondria. This can lead to diseases like Leber's hereditary optic neuropathy.

A network of interconnected tubules involved in protein synthesis and transport. It's divided into rough ER (rER) and smooth ER (sER).

A type of ER with ribosomes attached to its surface. It manufactures all proteins secreted by the cell.

A type of ER without ribosomes. It processes proteins synthesized in the rER, synthesizes lipids, and detoxifies drugs.

A stack of flattened membrane-bound sacs called cisternae involved in packaging and processing proteins and lipids. It has two faces: cis and trans.

Short, hair-like projections that move in a coordinated manner to move material outside the body. Flagella are longer, whip-like projections that propel sperm cells.