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Chapter 4. The Cell: Anatomy and Division. The Anatomy of a Cell. Figure 3.2. A typical cell. Nucleus DNA bound to histones Chromatin Chromosomes Chromatids Nucleoli Nuclear membrane Nuclear pores. The Nucleus. The Plasma Membrane. The Plasma Membrane . Selective permeability
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Chapter 4 The Cell: Anatomy and Division
The Anatomy of a Cell Figure 3.2
A typical cell • Nucleus • DNA bound to histones • Chromatin • Chromosomes • Chromatids • Nucleoli • Nuclear membrane • Nuclear pores
The Plasma Membrane • Selective permeability • Microvilli • Fingerlike projections
The cytoplasm contains: • The fluid (cytosol) • The organelles the cytosol surrounds
Ribosomes • Are responsible for manufacturing proteins • Are composed of a large and a small ribosomal subunit • Contain ribosomal RNA (rRNA) • Can be free or fixed ribosomes
Endoplasmic reticulum • Intracellular membranes involved in synthesis, storage, transportation and detoxification • Forms cisternae • Rough ER (RER) contains ribosomes • Modifies and stores new proteins • Transports new proteins to other areas of the cell • Smooth ER (SER) • Involved in lipid synthesis
Golgi Apparatus • Forms secretory vesicles • Discharged by exocytosis • Forms new membrane components • Packages lysosomes
Lysosomes and Peroxisomes • Lysosomes are • Filled with digestive enzymes • Responsible for autolysis of injured cells • Peroxisomes • Carry enzymes that neutralize alcohol, hydrogen peroxide and other harmful chemicals
Mitochondria • Responsible for ATP production through aerobic respiration • Matrix = fluid contents of mitochondria • Cristae = folds in inner membrane
Centrioles • Direct the formation of the mitotic spindle during cell division • Forms the base of cilia and flagella
Cytoskeleton provides strength and flexibility • Supports and moves substances within the cell • Microfilaments • Intermediate filaments • Thick filaments • Microtubules
Interphase • Most somatic cells spend the majority of their lives in this phase • Interphase includes • G1 – centrioles replication starts • S – DNA replication, centriole replication • G2 – centriole replication ends
Mitosis, or nuclear division, has four phases • Prophase • Metaphase • Anaphase • Telophase
Cytokinesis • It is the division of the cytoplasm • Cleavage furrow