Chapter 6: Cellular Organelles Functions and Structures (without pictures)

nucleus

control center of the cell, contains DNA which guides the cell's growth, development, and functioning

nucleolus

found inside the nucleus and produces ribosomes

ribosomes

site of protein synthesis

endomembrane system

regulates protein traffic and performs metabolic functions in the cell

endoplasmic reticulum

a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another

golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins and other molecules from the endoplasmic reticulum into vesicles

lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

vacuoles

cell organelle that stores materials such as water, salts, proteins, and carbohydrates

mitochondria

powerhouse of the cell, organelle that is the site of ATP (energy) production through cellular respiration

chloroplasts

organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis

peroxisomes

contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals and can break down fatty acids

microtubules

tiny tubes that give cells their shape and help them perform essential functions

microfilaments

tiny filaments in cells that contribute to their structure and enable important functions like movement and division

intermediate fibers

rope-like assemblies of fibrous polypeptides that support the nuclear envelope, plasma membrane, and form cell-to-cell junctions

cytoplasm

a jellylike fluid inside the cell in which the organelles are suspended

cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

plasmodesmata

an open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells

tight junctions

a specialized connection of two adjacent animal cell membranes such that the space usually lying between them is absent, prevents the leakage of fluid and molecules between the cells and helps maintain the integrity of the tissue barrier

gap junctions

provide cytoplasmic channels between adjacent cells to allow for direct communication and exchanging of ions, small molecules, and signaling molecules

desmosomes

anchoring junctions that prevent cells from being pulled apart

magnification

the increase of an object's apparent size

organelle

specialized structure that performs important cellular functions within a eukaryotic cell

artifacts

unintended or artificial features seen in biological samples under a microscope, often caused by the preparation methods

plasma membrane

the protective outer layer of a cell, controlling what goes in and out of the cell

nuclear envelope

double membrane perforated with pores that control the flow of materials in and out of the nucleus.

vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

lumen

hollow or interior space enclosed by a biological structure, allowing substances, such as blood, nutrients, or cellular products, to pass through or be contained within the structure

phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell

cristae

inward folds in the mitochondria's inner membrane that enhance the organelle's efficiency in producing energy for the cell

endocytosis

process by which a cell takes material (through a vesicle) into the cell by infolding of the cell membrane

pinocytosis

a type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

exocytosis

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane