Cells: Structure and Function

(1) cell metabolism & energy use (2) synthesis of molecules (3) communication (4) reproduction and inheritance

list the four main functions of a cell

large organelle usually in the center, bounded by a nuclear envelope, which has inner and outer membranes with a narrow space between them, and nuclear pores in the membranes

describe the structure of the nucleus

store, protect, and manage all the cell’s genetic material to control all cellular activities

describe the function of the nucleus

dense, innermost region of the nucleus

describe the structure of the nucleolus

produce and assemble ribosomes

function of the nucleolus

has ribosomes

structure of rough ER

protein synthesis

function of the rough ER

no ribosomes

structure of the smooth ER

lipid synthesis, cellular detoxification, and storage of calcium ions

function of the smooth ER

collects, modifies, and packages proteins and lipids

role of Golgi apparatus

break down molecules and particles using enzymes

describe the role lysosomes

break down fatty acids, amino acids, and hydrogen peroxide using enzymes

role of peroxisomes

sorts proteins and lipids into secretory vesicles

role of golgi apparatus in secretion

store and transport materials outside of the cell

role of secretory vesicles in secretion

inner and outer membranes separated by a space; outer membranes have smooth contour; inner membranes have folds called cristae

structure of mitochondria

produce ATP by aerobic metabolism

function of mitochondria

network of protein fibers that extend through the cytoplasm

structure of cytoskeleton

provide support, hold organelles in place, enable cell to change shape

function of cytoskeleton

oriented perpendicular to each other; small cylindrical organelle composed of microtubules

structure of centrioles

help organize the cell’s cytoskeleton and direct cell division

function of centrioles

project from the surface of some cells; cylindrical structures made of microtubules

structure of cilia

movement of materials over the top of the cell; ex: mucus

function of cilia

similar to cilia, but much longer; composed of microtubules; only one per cell

structure of flagella

cell movement

function of flagella

abundant on surface of cells that line intestine, made up of microfilaments; specialized extensions of the cell membrane

structure of microvilli

increase surface area of cells

function of microvilli

chromatin

during most of the cell’s life, chromosomes are loosely coiled and collectively called

free ribosomes

ribosomes that are not attached are called

produce proteins

function of ribosomes

microtubules, intermediate filaments, microfilaments

cytoskeleton proteins: largest to smallest diameter

provide structural support; form cilia and flagella; assist in cell divison

microtubules do what

maintain cell shape; provide mechanical support to the cell

intermediate filaments do what

involved in cell movement; determine cell shape

purpose of microfilaments

in the centrosome

where does microtubule formation occur?