Chapter 4

Question 1

plasma membrane

Answer 1

separates internal contents of cell from external environment. contain cilia, flagellum, and microvilli. has polar heads and 2 hydrophobic tails. Cholesterol strengthens the membrane and protects against temp. Glycolipids for coating of sugar on cell surface

Question 2

nucleus

Answer 2

largest structure in cell; contains genetic material and a fluid called nucleoplasm.

Question 3

cytoplasm

Answer 3

cellular contents between plasma membrane and nucleus. includes cytosol, organelles, and inclusions.

Question 4

cytosol

Answer 4

viscous fluid in the cytoplasm

Question 5

inclusions

Answer 5

large diverse group of molecules not bound by membranes. (ex: pigment, glycogen, triglycerides)

Question 6

general cell functions

Answer 6

maintain integrity and shape of cell, obtain nutrients and form chemical building blocks, dispose of waste. some cells go through division

Question 7

integral proteins

Answer 7

embedded within lipid bilayer and extend across. often glycoproteins with carb portion

Question 8

peripheral proteins

Answer 8

attached loosely to surface of lipid bilayer

Question 9

passive transport

Answer 9

does not require energy and moves substances down their concentration gradients. includes diffusion and osmosis

Question 10

osmosis

Answer 10

travel of water into or out of the cell.

Question 11

tonicity

Answer 11

ability of a solution to change the volume or pressure of the cell by osmosis

Question 12

isotonic

Answer 12

no net movement of water; in the body the cell and outside have 0.9% NaCl

Question 13

hypotonic

Answer 13

solution with lower solute than cell. Moves water into the cell and ma cause lysis or rupturing

Question 14

hypertonic

Answer 14

solution with higher concentration of solutes than cell. Water moves out and causes cell to crenate or shrink

Question 15

active transport

Answer 15

require energy, can move substances up its concentration gradient

Question 16

ion pumps

Answer 16

active transport proteins that move ions across membrane. Helps cell maintain internal concentration of ions.

Question 17

vesicular transport

Answer 17

requires vesicles and energy. exocytosis and endocytosis

Question 18

exocytosis

Answer 18

vesicle fuses with membrane and releases substances out of cell

Question 19

endocytosis

Answer 19

vesicle encloses material outside cell and fuses with membrane to bring into cell

Question 20

phagocytosis

Answer 20

when a cell engulfs particle external to cell. only in a few cell types like white blood cells

Question 21

pinocytosis

Answer 21

internalization of drops of interstitial fluid. multiple vesicles form and solutes are taken into cell. performed by most cells

Question 22

endoplasmic reticulum

Answer 22

separates fluid within structure from cytosol, extends from nuclear envelope, point of attachment for ribosomes, and point for insertion of enzymes.

Question 23

rough er

Answer 23

protein and peroxisome production, plentiful in cells producing a lot of protein

Question 24

smooth er

Answer 24

synthesis, transport, and storage of lipids, carb metabolism, detox. plentiful in testes and liver

Question 25

Golgi apparatus

Answer 25

composed of saclike structures called cisternae. “warehouse of the cell. functions include modification, packaging, and sorting proteins, transport of material from cis face to trans face, and formation of secretory vesicles and lysosomes

Question 26

lysosomes

Answer 26

small sacs that contain digestive enzymes from the Golgi. digest unneeded substances and contents of endocytosed vesicles

Question 27

peroxisomes

Answer 27

pinched off vesicles from rough er. Smaller than lysosomes and contain oxidative enzymes. serve in detoxification by producing hydrogen peroxide. engage in beta oxidation of fatty acid. most abundant in liver

Question 28

mitochondria

Answer 28

aerobic cellular respiration and complete digestion of fuel molecules to make atp

Question 29

ribosomes

Answer 29

contain protein and ribonucleic acid. have a large (with e, p, and a sites) and small subset. bound ribosomes make proteins for plasma membrane, export, or lysosomes. free ribosomes make all other proteins

Question 30

cytoskeleton

Answer 30

plays role in intracellular support, organization of organelles, cell division, and movement of materials. also anchors proteins in plasma membrane. includes microfilaments, intermediate filaments, and microtubules.

Question 31

centrosome

Answer 31

close proximity to nucleus and contains pair of perpendicularly oriented cylindrical centrioles. organizes microtubules within cytoskeleton and aids in cell division

Question 32

proteasomes

Answer 32

large barrel-shaped complexes that digest proteins with a ubiquitin tag.

Question 33

cilia

Answer 33

found on surface of specific cells such as in the respiratory tract to move substances

Question 34

flagella

Answer 34

propels entire cell

Question 35

microvilli

Answer 35

microscopic extensions from surface of plasma membrane. supported by microfilaments and increase surface area to absorb nutrients.

Question 36

nuclear envelope

Answer 36

double phospholipid membrane enclosing nucleus. contains nucleoplasm and is continuous with rough er. Contains passageways called nuclear pores.

Question 37

Cell division

Answer 37

necessary for development, tissue growth and repair, and replacement of old cells. mitosis occurs in somatic cells and meiosis in sex cells.