A&p1 Lab: Exercise 4

Front 1

Nucleus

Back 1

round structure near center of the cell; contains DNA

Front 2

Chromatin

Back 2

DNA in threadlike form, dispersed throughout the nucleus

Front 3

Chromosomes

Back 3

Chromatin coiled and condensed, in this form for cell division

Front 4

Nucleoli

Back 4

small round bodies in the nucleus, composed of proteins and RNA. Assembly sites for ribosomes.

Front 5

Nuclear envelope

Back 5

Double-layered porous membrane that binds the nucleus. Has nuclear pores to permit passage of proteins and RNA.

Front 6

Plasma Membrane

Back 6

Separates cell contents from surrounding environment. Made of a phospholipid bilayer with dispersed protein molecules. Has selective permeability.

Front 7

Microvilli

Back 7

Fingerlike projections or folds in the plasma membrane that increases surface area to increase absorption of materials and binding of signaling molecules.

Front 8

Cytosol

Back 8

Fluid cytoplasmic material inside the cell.

Front 9

Organelles

Back 9

Metabolic machinery of the cell including ribosomes, ER, Golgi apparatus, lysosomes, peroxisomes, mitochondria, cytoskeletal elements, and centrioles.

Front 10

Ribosomes

Back 10

Tiny spherical bodies composed of RNA and protein; sites of protein synthesis; free floating or attached to rough ER

Front 11

Endoplasmic Reticulum (ER)

Back 11

Membranous system of tubules. Rough ER- studded with ribosomes; tubules provide storage and transport of the proteins made; external face synthesizes phospholipids and cholesterol
Smooth ER- site of steroid and lipid synthesis, lipid metabolism, and drug detoxification

Front 12

Golgi Apparatus

Back 12

Stack of flattened sacs with bulbous ends and associated small vesicles; plays a role in packaging proteins or other sub.s for export from the cell and in packaging lysosomal enzymes

Front 13

Lysosomes

Back 13

Membranous sacs containing digestive enzymes (acid hydrolases); digests worn-out organelles and foreign sub.s that enter the cell; can destroy entire cell if ruptured

Front 14

Peroxisomes

Back 14

Membranous sacs containing oxidase enxymes that detoxify harmful substances, incl. free radicals

Front 15

Mitochondria

Back 15

Rod-shaped bodies w/ a double-membrane wall; inner membrane is thrown into cristae; contains enzymes that oxidize foodstuffs into ATP; the "powerhouse of the cell"

Front 16

Centrioles

Back 16

Paired, cylindrical bodies lie close to the nucleus; direct the formation of the mitotic spindle during cell division; form bases of cilia and flagella

Front 17

Inclusions

Back 17

Other substances stored in the cytoplasm, incl. glycogen granules, lipid droplets, pigment granules, various crystals, water vacuoles, and ingested foreign materials.

Front 18

Cytoskeletal elements

Back 18

Microfilaments- formed of actin, important in cell motility
Intermediate filament- stable, composed of proteins, resist mechanical forces on a cell
Microtubules- form internal structure of centrioles and determine cell shape

Front 19

Interphase

Back 19

Period from cell formation to cell division. 4 subphases:
G1 (gap 1)-vigorous growth & metabolism
G0- gap phase in cells that will no longer divide (permanent)
S (synthetic)- DNA replication
G2 (gap 2)- prep for division

Front 20

Mitosis

Back 20

Nuclear division

Front 21

Cytokinesis

Back 21

Division of the cytoplasm. Ring of actin microfilaments contracts to form a cleavage furrow. 2 daughter cells are pinched apart. Begins in late anaphase and continues through and beyond telophase.

Front 22

Meiosis

Back 22

A specialized type of nuclear division that occurs in the reproductive organs. Results in 4 daughter cells with half the chromosomes.

Front 23

Early Prophase

Back 23

Chromosome become visible, each with two chromatids joined at a centromere with cohesin(an adhesive protein). The nucleoli disappear. Centrosomes separate and migrate toward opposite poles. Mitotic spindles and asters form around the centrioles.

Front 24

Late Prophase

Back 24

Nuclear envelope fragments. Kinetochore microtubules attach to kinetochore of centromeres and draw them toward the equator of the cell. Polar microtubules are linked in the center and, pushing against each other, they assist in forcing the poles apart.

Front 25

Metaphase

Back 25

Centromeres of chromosomes are aligned at the equator. This plane midway between the poles is called the metabolic plate. The enzyme separase cleaves cohesin, separating the chromatids.

Front 26

Anaphase

Back 26

Centromeres of chromosomes split simultaneously- ea. chromatid becomes a chromosome. Chromosomes (V-shaped) are pulled toward poles by motor proteins of kinetochores. Polar microtubules cont. forcing the poles apart.

Front 27

Telophase

Back 27

Begins when chromosome movement stops. The two sets of chromosomes uncoil to form chromatin. New nuclear membranes form around each chromatin mass. Nucleoli reappear. Spindle disappears.

Front 28

Back 28

Interphase

Front 29

Back 29

Late prophase

Front 30

Back 30

Metaphase

Front 31

Back 31

Anaphase

Front 32

Back 32

Telophase/ Cytokinesis

Front 33

Back 33

Early prophase