Chapter 3 - The Cell

Question 1

Cytoplasm

Answer 1

material between plasma membrane and the nucleus

Question 2

Cytosol

Answer 2

largely water with dissolved protein, salts, sugars, and other solutes

Question 3

Cytoplasmic organelles

Answer 3

metabolic machinery of the cell

Question 4

Mitochondria

Answer 4

Double membrane structure with shelf like cristae
Provide most of the cell’s ATP via aerobic cellular respiration
Contain their own DNA and RNA

Question 5

Endoplasmic Reticulum

Answer 5

Interconnected tubes and parallel membranes enclosing cisternae
Continuous with the nuclear membrane
Two varieties – rough ER and smooth ER

Question 6

Golgi Apparatus

Answer 6

Stacked and flattened membranous sacs

Functions in modification, concentration, and packaging of proteins

Question 7

Lysosomes

Answer 7

Spherical membranous bags containing digestive enzymes
Digest ingested bacteria, viruses, and toxins
Degrade nonfunctional organelles

Question 8

Peroxisomes

Answer 8

Membranous sacs containing a variety of enzymes
Detoxify harmful or toxic substances
Very numerous in liver and kidney cells
Oxidases and catalases neutralize dangerous free radicals
Free radicals – highly reactive chemicals with unpaired electrons (i.e., O2–)
Look like lysosomes but are self replicating, no Golgi apparatus needed.

Question 9

Ribosomes

Answer 9

Granules containing protein and rRNA
Site of protein synthesis
Free ribosomes synthesize soluble proteins
Membrane-bound ribosomes synthesize proteins to be incorporated into membranes

Question 10

Endomembrane System

Answer 10

System of organelles that function to:
Produce, store, and export biological molecules
Degrade potentially harmful substances
System includes:
Nuclear envelope, smooth and rough ER, lysosomes, vacuoles, transport vesicles, Golgi apparatus, and the plasma membrane

Question 11

Microfilaments

Answer 11

Dynamic strands of the protein actin
Attached to the cytoplasmic side of the plasma membrane
Braces and strengthens the cell surface
Attach to CAMs (cell adhesion molecules), function in cell division, ameboid motion, endocytosis and exocytosis,

Question 12

Intermediate Filaments

Answer 12

Tough, insoluble proteins
Diameter between that of MF and MT (that’s why they are called Intermediate Filaments)
Look like ropes with high tensile strength
Most stable and permanent
Form internal structure, ie, keratin in epithelials

Question 13

Microtubules

Answer 13

Dynamic, hollow tubes made of the spherical protein tubulin
Determine the overall shape of the cell and distribution of organelles
Organelles, lysosomes and secretory granules move along the MT by motor proteins

Question 14

Centrioles

Answer 14

Small barrel-shaped organelles located in the centrosome near the nucleus
Pinwheel array of nine triplets of microtubules
Organize mitotic spindle during mitosis
Form the base of cilia and flagella

Question 15

Cilia

Answer 15

Whiplike, motile cellular extensions on exposed surfaces of certain cells
Move substances in one direction across cell surfaces

Question 16

Flagella

Answer 16

Sperm

Question 17

Nuclear Envelope

Answer 17

Selectively permeable double membrane barrier containing pores
Outer membrane is continuous with the rough ER and is studded with ribosomes
Inner membrane is lined with the nuclear lamina, which maintains the shape of the nucleus
Pore complex regulates transport of large molecules into and out of the nucleus

Question 18

Nucleoli

Answer 18

Dark-staining spherical bodies within the nucleus

Site of ribosome production

Question 19

Chromatin

Answer 19

Threadlike strands of DNA and histones
Arranged in fundamental units called nucleosomes
Form condensed, barlike bodies of chromosomes when the nucleus starts to divide

Question 20

Cell Cycle

Answer 20

Interphase
Growth (G1), synthesis (S), growth (G2)
 Mitotic phase
	Prophase
	Metaphase
	Anaphase
	Telophase
 Cytokinesis
Biology is the only science in which multiplication 
means the same thing as division.

Question 21

Protein Synthesis

Answer 21

DNA serves as master blueprint for protein synthesis

Genes are segments of DNA carrying instructions for a polypeptide chain