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

Functions of Organelles Nucleolus Reservoir for RNA Ribosomes Serve as site for protein synthesis

Functions of Organelles Cytoplasm Provides an organized watery environment where life functions take place via the activities of the organelles, which reside there Centrosome Contains two centrioles that are functional during animal cell division

Functions of Organelles Endoplasmic reticulum Provides passage for the transport of substances in the cytoplasm Mitochondria Serve as sites of cellular respiration and energy production Store ATP

Functions of Organelles Golgi apparatus Manufactures carbohydrates and packages secretions for discharge from the cell Lysosomes Serve as center for cellular digestion

Functions of Organelles Perioxisomes Enzymes that oxidize cell substances Cytoskeleton Forms internal framework

Functions of Organelles Pinocytic vesicles Provide mechanism 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 that we eat

Cell Division Meiosis Mitosis Involves reproduction 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 Phase II Phase III Interphase (resting stage) Prophase Phase III Metaphase

Mitosis Stages Phase IV Phase V Cycle back to interphase Anaphase Telophase Cycle back to interphase

Cell Death Necrosis Apoptosis

Stem Cells Embryonic stem cells Adult stem cells Umbilical cord blood stem cells Induced pluripotent stem cells

Protein Synthesis Cells produce proteins DNA RNA

Movement of Materials Across Cell Membranes Passive transport Does not require an energy source Active transport Requires an energy source

Passive Transport Diffusion Osmosis Filtration

Active Transport Phagocytosis Pinocytosis

Active Transport © 2014 Cengage Learning.

Specialization Nerve cells Red blood cells Specialize in response Red blood cells Specialize in oxygen transport May lose some functions, such as reproduction Interdependence among cells

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