Unit 4 {Cells}

Question 1

Hooke (1665)

Answer 1

first to use the term “cell” to describe the structures that make up all living things, observed cork cells (dead)

Question 2

Leeuwenhoek (1670’s)

Answer 2

father of modern microbiology, first to observe living cells

Question 3

Cell Theory

Answer 3

1) all organisms are composed of one or more cells 2) cells are the basic units of structure and function for all living things 3) cells arise only from other pre-existing cells

Question 4

Prokaryotic Cells

Answer 4

simplest and most ancient types of cell, found only in bacteria; no nucleus and no membrane bound organelles, no complex organelles, single celled

Question 5

Eukaryotic Cells

Answer 5

more modern and complex cells, contain nucleus and “membrane-bound” organelles, found in plants/animals/fungi/protists

Question 6

Cell Membrane

Answer 6

outer boundary of the cell; separates the cell from the external environment, regulates what goes in and out of the cell

Question 7

Cytosol (Cytoplasm)

Answer 7

clear fluid filling the cell in which organelles are suspended

Question 8

Nucleus

Answer 8

contains the genetic material; controls the activities of the cell, surrounded by nuclear membrane

Question 9

Nucleolus

Answer 9

found within nucleus, site where ribosomes are made

Question 10

Endoplasmic Reticulum *smooth E.R = no ribosomes; rough E.R = with ribosomes)

Answer 10

“intracellular highway” : system of transport tubules within the cell

Question 11

Ribosomes- free floating vs. attached to E.R

Answer 11

location where protetins are assembled; most numerous organelle

Question 12

Golgi Apparatus

Answer 12

packaging and processing organelle; proteins are modified and prepared for export

Question 13

Mitochondria

Answer 13

“powerhouse” of the cell; location where ATP is made by aerobic respiration

Question 14

Lysosome

Answer 14

contain digestive enzymes, breaks down foods and worn out cell parts

Question 15

Peroxisome

Answer 15

small and membrane bound, contains toxic peroxides that are safely broken down

Question 16

Cytoskeleton

Answer 16

provides shape and support for the cell

Question 17

Vacuole

Answer 17

storage organelles, stores materials and wastes

Question 18

Centrioles

Answer 18

aids in cell division

Question 19

Cell Walls

Answer 19

found outside cell membrane, made of cellulose, provides support to cell

Question 20

Chloroplasts (type of Plastid)

Answer 20

contains chlorophyll, site of photosynthesis

Question 21

Chromoplasts (type of Plastid)

Answer 21

contain accessory pigments that aid in photosynthesis

Question 22

Leukoplasts

Answer 22

stores starch

Question 23

Passive Transport

Answer 23

movement of materials across a membrane which requires no energy (besides kinetic energy)

Question 24

Simple Diffusion

Answer 24

driven completely by kinetic energy of particles, may or may not include a membrane, movement of materials from area of high concentration to area of low concentration

Question 25

Concentration Gradient

Answer 25

exists when there is a difference in concentrations over a distance or across a membrane

Question 26

Equilibrium Rate of Diffusion

Answer 26

no concentration gradient; equal concentrations, due to diffusion pressure, mass of molecule, and temperature

Question 27

Semi-Permeable Membrane

Answer 27

lets only selected sbstances through, based on size and polarity of molecules

Question 28

Facilitated Diffusion

Answer 28

form of passive transport in which substances move from an area of high concentration to an area of low concentration with the assistance of proteins in the membrane

Question 29

Osmosis

Answer 29

passive transport of water across a membrane from high concentration to low concentration

Question 30

Isotonic Environment

Answer 30

state of equilibrium, equal concentrations throughout both inside and outside of cell, no concentration gradient exists, zero diffusion pressure

Question 31

Hypotonic Environment

Answer 31

concentration of solutes outside is lower than concentration of solutes inside the cell

Question 32

Hypertonic Environment

Answer 32

concentration of solutes outside the cell is greater than the concentration inside the cell

Question 33

Turgor Pressure

Answer 33

pressure that builds up in a cell due to the inward flow of water

Question 34

Plasmolysis

Answer 34

shrinking of a cell from loss of water

Question 35

Cytolysis

Answer 35

swelling and bursting of a cell caused by internal pressure

Question 36

Active Transport

Answer 36

passage of a substance across a semi-permeable membrane that requires the use of ATP energy, may be the movement of materials against the concentration gradient or movement of molecules too large for the membrane pores

Question 37

Ion Pumps

Answer 37

carrier proteins used to move ions across the membrane against the concentration gradient, conformational change of carrier proteins require ATP, used to maintain steep concentration gradient of ions across a cell membrane

Question 38

Endocytosis

Answer 38

taking in large molecules by a cell without moving through pores of cell membrane, formation of vesicles when the cell membrane pinches off

Question 39

Receptor-Mediated Endocytosis

Answer 39

acquiring in large molecules by a cell without moving through used of receptor proteins found at specific sites (coated pits) on the outer surface of the cell membrane, when receptor proteins bind to the appropriate macromolecules outside the cell, the coated pit invaginates (folds inward) to form a vacuole

Question 40

Phagocytosis

Answer 40

engulfing whole cells or single-celled organisms; formation of vacuoles, broken down by digestive enzymes of lysosomes

Question 41

Pinocytosis

Answer 41

taking in liquids or large molecules by a cell; formation of vacuoles, broken down by digestive enzymes of lyosomes

Question 42

Exocytosis

Answer 42

passage of large molecules to the outside of the cell without going through pores of the cell membrane, vesicles fuse with the cell membrane as the molecule is released outside the cell