Anatomy: Exercise 4 The Cell: Anatomy And Division

Front 1

Nucleus

Back 1

Contains the genetic material DNA, sections of which are called genes. . Often described as the control center of the cell, necessary for cell reproduction.

Front 2

Chromatin

Back 2

When cell is not dividing, genetic material loosely dispersed throughout nucleus in threadlike form

Front 3

Chromosomes

Back 3

When cell is dividing to form daughter cells, chromatin coils and condenses, forming dense, rod like bodies

Front 4

Nucleoli

Back 4

Small spherical bodies composed primarily of proteins and ribonucleic acid (RNA). Assembly sites for ribosomes those are abundant in the cytoplasm

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Nuclear Envelope

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Double layered porous membrane enclosing nucleus.Distinguishable to other cellular membranes because of its large nuclear pores

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Nuclear Pores

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Spanned by protein complexes that regulate what passes through, permits easy passage of protein and RNA molecules

Front 7

Plasma Membrane

Back 7

Separates cell contents from the surrounding environment,providing a protective barrier. Main structural building blocks are phospholipids (fats) and globular protein molecules. Some of the externally facing proteins and lipids have sugar (carbs) side chains attached to them that are important in cellular interactions

Front 8

Selective Permeability

Back 8

Because of its molecular composition, plasma membrane allows nutrients to enter the cell but keeps out undesirable substances. Valuable cell proteins and other substances are kept, while excreta or wastes pass to the exterior

Front 9

Microvilli

Back 9

Fingerlike projections or folds that increase surface area of the cell available for absorption or passage of materials and for the binding of signaling molecules

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Cytoplasm

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Consists of the cell contents between the nucleus and the plasma membrane

Front 11

Cytosol

Back 11

Fluid cytoplasmic material

Front 12

Organelles

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Small structures which are the metabolic machinery of the cell and highly organized to carry out specific functions for the cell as a whole

Front 13

Ribosomes

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Tiny spherical bodies composed of RNA and protein; floating free or attached to a membranous structure (rough ER). Actual sites of protein synthesis

Front 14

Endoplasmic reticulum

Back 14

Membranous system of tubules; two varieties. Rough is studded with ribosomes; tubules provide an area for storage and transport of the proteins made on the ribosomes to other cell areas. Smooth has no function in protein synthesis, site of steroid and lipid synthesis, lipid metabolism,and drug detoxification

Front 15

Golgi Apparatus

Back 15

Stack of flattened sacs with bulbous ends andassociates small vesicles; close to nucleus. Packages proteins and othersubstances to export from the cell or incorporation into the plasma membrane and in packaging lysosomal enzymes

Front 16

Lysosomes

Back 16

Various sized membranous sacs containing digestive enzymes including acid hydrolases; function to digest worn out cell organelles and foreign substances. Capacity of total destruction if ruptured and are for this reason referred to as “suicide sacs"

Front 17

Peroxisomes

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Small lysosome like sacs containing oxidase enzymes that detoxify alcohol, free radicals, and other harmful chemicals. Abundant in liver and kidney cells

Front 18

Mitochondria

Back 18

- Generally rod shaped bodies with double membrane wall; inner is shaped into folds called cristae; contain enzymes that oxidize foodstuffs to produce cellular energy (ATP); often referred to as the “powerhouses of the cell.”

Front 19

Centrioles

Back 19

- Paired, cylindrical bodies that lie at right angles to each other, close to nucleus. Composed of nine triplets of microtubules. As part of centrosome, direct formation of the mitotic spindle during cell division; form the bases of cilia and flagella and in that role are called “basal bodies.”

Front 20

Cytoskeletal elements

Back 20

- Microfilaments, intermediate filaments and microtubules: Form internal scaffolding called the cytoskeleton. Provide cellular support; function in intracellular transport. Microfilaments formed largely of actin, contractile protein, thus are important in cell mobility (muscle cells.) Intermediate filaments are stable elements composed of a variety of proteins and resist mechanical forces acting on cells. Microtubules form the internal structure of the centrioles and help determine cell shape.

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Cell Division: Mitosis and Cytokinesis Stages

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Interphase - Prophase - Metaphase - Anaphase - Telophase - Cytokinesis

IPMATC

I Pretend My Anatomy Teacher Cares

Front 22

Interphase

Back 22

First of two stages that cell’s life cycle undergoes from the time it is formed to until it reproduces. Longer period during which the cell grows and carries out its usual activities. G1 phase is when centrioles begin replicating. S phase is when DNA is replicated. G2 phase is when centrioles finish replicating

Front 23

Cell Division

Back 23

When about to divide, DNA is replicated. Other than bacteria, cell division consists of mitosis and cytokinesis. Function is to increase the number of cells for growth and repair

Front 24

Mitosis

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Division of the copied DNA of the mother cell to 2 daughter nuclei

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Meiosis

Back 25

Specialized type of nuclear division that occurs only in the reproductive organs (testes or ovaries). Yields 4 daughter nuclei that differ genetically in composition from the mother nucleus, and used only for the production of gametes (eggs and sperm) for sexual reproduction.

Front 26

Prophase

Back 26

Chromatin becomes chromosomes, which consist of two identical threads called sister chromatids, held together at the centromere. Nucleoli disappear; centrosomes separate and act as focal points of growth of a microtubule assembly called the mitotic spindle. These arrays are called asters

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Metaphase

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Chromosomes cluster with their centromeres precisely aligned at the equator of the spindle, also called the metaphase plate. Enzymes separate chromatids from each other.

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Anaphase

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Centromeres split, push the two poles of the cell apart.

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Telophase

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Prophase in reverse

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Phospholipid

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- Composed of two fatty acids (long chains of hydrogen and carbon molecules C-H), a glycerol 'head', a phosphate group and a polar molecule. The phosphate group and polar head region of the molecule is hydrophillic (attracted to water), while the fatty acid tail is hydrophobic (repelled by water).

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2 Types of Protein in Plasma Membrane

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Integral Proteins

Peripheral Proteins

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Integral Proteins

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- Structures within the plasma membrane that assist relaying signals between the cell's internal and external environments and moving molecules and ions across the membrane

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Peripheral Proteins

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- Do not interact with the hydrophobic core of the phospholipid bilayer

- Instead usually bound to the membrane indirectly by interactions with integral membrane

Front 34

Glycocalyx (Carbohydrates)

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-Sugar side chains attached to the hydrophillic glycerol 'head' and phosphate group of the outer phospholipid bilayer.

Front 35

Cholesterol

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- Lipids within the cell membrane that help give the cell membrane extra support

- Helps to immobilize some of the lipid molecules around them and makes the cell membrane stronger, thus makes it harder for small molecules to pass through the membrane

Front 36

Inclusions

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stored glycogen granules, crystals, pigments, and so on