© 2009 Delmar, Cengage Learning Chapter 3 Cells. © 2009 Delmar, Cengage Learning Cells The cell is...

© 2009 Delmar, Cengage Learning

Chapter 3

Cells


Cells

• The cell is the basic unit of structure and function of all living things

• Cell or plasma membrane

• Nucleus


Nucleus

• Most important organelle within the cell

• Function– Control the activities of the cell and facilitate cell division

• DNA and chromatin

• Chromosomes


Functions of Organelles

• Nuclear membrane or nuclear envelope– Regulates transport of substances into and out of the cell

• Nucleoplasm– A clear, semi-liquid medium that fills the spaces around the

chromatin and the nucleoli



• Nucleolus– Reservoir for RNA

• Ribosomes– Serves at site for protein synthesis



• Cytoplasm– Provides an organized watery environment, in which life

functions take place by the activities of the organelles contained in the cytoplasm

• Centrosome– Contains two centrioles that are functional during animal cell

division



• Endoplasmic reticulum– Provides passage through which transport of substances occurs

in cytoplasm

• Mitochondria– Serves as sites of cellular respiration and energy production;

stores ATP



• Golgi apparatus– Manufactures carbohydrates and packages secretions for

discharge from the cell

• Lysosomes– Serve as center for cellular digestion



• Perioxisomes– Enzymes oxidize cell substances

• Cytoskeleton– Forms internal framework



• Pinocytic vesicles– Method by which large molecules can enter the cell

• Cilia and flagella– Create movement


Cellular Metabolism

• Chemical reactions occur within the cells

• Energy supplied by ATP

• ATP created from CHO, proteins, and fats we eat


Cell Division

• Meiosis– Involves reproduction

• Mitosis– Involves growth and maintenance of cells


Meiosis

• Process of cell division of the sex cell or gamete

• Ovum and spermatozoa reduce chromosomes from 46 to 23

• Fertilization

• Zygote is formed from two sex cells to obtain full set of 46 chromosomes


Mitosis

• Cell division– Division of the nucleus

– Division of the cytoplasm


Mitosis Stages

• Phase I– Interphase (resting stage)

• Phase II– Prophase

• Phase III– Metaphase


Mitosis Stages

• Phase IV– Anaphase

• Phase V– Telophase

• Cycle back to interphase


Cell Death

• Necrosis

• Apoptosis


Stem Cells

• Embryonic stem cells

• Adult stem cells

• Umbilical cord blood stem cells


Protein Synthesis

• Cells produce proteins

• DNA

• RNA


Movement of MaterialsAcross Cell Membranes

• Passive transport– Do not require an energy source

• Active transport– Require an energy source


Passive Transport

• Diffusion

• Osmosis

• Filtration


Active Transport

• Phagocytosis

• Pinocytosis


Specialization

• Nerve cells– Specialize in response

• Red blood cells– Specialize in oxygen transport

• May lose some functions, such as reproduction

• Interdependence among cells


Animation – Anatomyof a Typical Cell

Click Here to play Typical Cell animation


Aging

• Aging is a phase of normal development

• Older person may have 30% fewer cells

• Cells may change in ability to perform specialized tasks


Aging

• Physiologic changes are universal and progressive

• Aging is not a disease


Disorders of Cell Structure

• Atrophy

• Hypertrophy

• Hyperplasia


Disorders of Cell Structure

• Metaplasia

• Dysplasia

• Neoplasia


Tumor

• When cell division does not occur in the usual pattern

• Also called neoplasms

• Benign tumors

• Malignant tumors

© 2009 Delmar, Cengage Learning Chapter 3 Cells. © 2009 Delmar, Cengage Learning Cells The cell is...

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