Summary BIO 230 Chapter 3 Review Guide

Review Concepts:

Chapter 3: Cellular Level of Organization

Introduction to Cells
o Cell theory and the process of cellular differentiation.
o The cell and its organelles, including the structure and function of
each.
o Structural and functional features of the plasma membrane.
o The ribosome, smooth and rough endoplasmic reticula, and indicate
their specific functions.
o The Golgi apparatus and indicate its specific functions.
o Structure of a mitochondrion, and explain the significance of
mitochondria to cellular function.
o Smallest living unit in the body

Cell differentiation
o All cells in the body come from a single fertilized ovum
 Start with a single cell, yet end with wide variety of cell size,
shape, and function
o Fertilized ovum contains genetic potential to become any cell
o First cell divisions create smaller parcels of cytoplasm
o Regional differences in original ovum cytoplasm means now different
composition of cytoplasm in resulting daughter cells
o Cytoplasmic differences affect DNA in daughter cells and cause
specific genes to turn on or off
 Result is specialization of cells
 Process of gradual specialization is called differentiation
 Specialized cells form tissues of the body
Body fluid distribution
o Cells surrounded by extracellular fluid
 Watery medium surrounding cells
 Called interstitial fluid (interstitium, something standing
between) in most tissues
o Fluid inside cell is intracellular fluid or cytoplasm
o Cell plasma membrane separates intracellular from extracellular fluid
Basic cell structure
o Surrounded by a plasma membrane
o Contains cytoplasm
 Material of varying consistency found between cell membrane
and nuclear membrane
 Subdivided into:

, o Cytosol (intracellular fluid) – the fluid part of cytoplasm
o Organelles (“little organs”) – intracellular structures with
specific functions
Organelles
o Divided into membranous and nonmembranous
o Nonmembranous
 Not completely enclosed by membranes
 In direct contact with cytosol
 Examples:
o Cytoskeleton
o Microvilli
o Centrioles
o Cilia
o Ribosomes
o Membranous
 Enclosed in a phospholipid membrane
 Isolated from cytosol
 Examples:
o Mitochondria
o Nucleus
o Endoplasmic reticulum
o Golgi apparatus
o Lysosomes
o Peroxisomes
o Peroxisome
 STRUCTURE:
o Vesicles containing degradative enzymes
 FUNCTION:
o Break down organic compounds
o Neutralize toxic compounds
o Lysosome
 STRUCTURE:
o Vesicles containing digestive enzymes
 FUNCTION:
o Break down organic compounds and damaged
organelles or pathogens
o Microvilli
 STRUCTURE:
o Membrane extensions containing microfilaments
 FUNCTION:
o Increase surface area for absorption
o Golgi apparatus
 STRUCTURE:
o Stacks of flattened membranes (cisternae) containing
chambers
 FUNCTION:

, o Store, alter, and package synthesized products
o Nucleus
 STRUCTURE:
o Fluid nucleoplasm containing enzymes, proteins, DNA,
and nucleotides
o Surrounded by double membrane called nuclear
envelope
 FUNCTION:
o Controls metabolism
o Stores and processes genetic information
o Controls protein synthesis
o Endoplasmic reticulum (ER)
 STRUCTURE:
o Network of membranous sheets and channels
 FUNCTION:
o Synthesizes secretory products; stores and transports
within cell; detoxifies drugs and toxins
o Smooth ER
 No attached ribosomes
 Synthesizes lipids and carbohydrates
o Rough ER
 Attached ribosomes
 Modifies/packages newly synthesized proteins
o Ribosomes
 STRUCTURE: RNA and proteins
o Fixed: attached to endoplasmic reticulum
o Free: scattered in cytoplasm
 FUNCTION:
o Synthesize proteins
o Mitochondrion
 STRUCTURE:
o Double membrane
o Inner membrane contains metabolic enzymes
 FUNCTION:
o Produces 95 percent of cellular ATP
o Cytoskeleton
 STRUCTURE:
o Proteins organized into fine filaments or tubes
o Centrosome
 Organizing center containing pair of centrioles
 FUNCTION:
o Strengthens and supports cell
o Moves cellular structures and materials within the cell


Plasma Membrane