Slide 3

Front 1

Cell Theory

Back 1

-All organisms are composed of one or more cells

-Cells are the smallest living things

-Cells arise only by division of previously existing cells

Front 2

surface-to-volume ratio

Back 2

-limits cell size

-as cell size increases, the volume grows more rapidly than surface area

Front 3

plasma membrane

Back 3

-a fluid mosaic

-sheet of lipids with embedded proteins

-forms the boundary of the cell

-controls the permeability of the cell to water and dissolved substances

Front 4

cytoplasm

Back 4

fills the interior of the cell

Front 5

Plasma membrane-the interior lipid bilayer is completely . And contains ?

Back 5

nonpolar

Cholesterol-maintains integrity of membrane

Front 6

Can water soluble molecules cross through the plasma membrane?

Back 6

only water

Front 7

membrane proteins

Back 7

major component of the membrane

-transmembrane proteins

-cell surface proteins

Front 8

cell surface proteins

Back 8

-proteins are integrated into the structure of the membrane

-attached to the outer surface of the membrane and act as markers

Front 9

transmembrane proteins

Back 9

proteins form channels that span the membrane

Front 10

2 cell types

Back 10

prokaryotic

eukaryotic

Front 11

Prokaryotic cells

Back 11

Prokaryotes are the simplest cellular organisms

lacks a nucleus and does not have an extensive system of internal membranes

all bacteria and archaea have this cell type

Front 12

Organization of a prokaryotic cell

Back 12

cytoplasm>>ribosomes>>nucleoid region

Front 13

Cytoplasm

Back 13

the contents of the cell enclosed by the plasma membrane

Front 14

ribosomes

Back 14

(sites for protein synthesis)

are scattered throughout the cytoplasm

Front 15

nucleoid region

Back 15

(an area of the cell where DNA is localized)

not membrane-bound, so not a true nucleus

Front 16

Other structures sometimes found in prokaryotes relate to locomotion, feeding, or genetic exchange

Back 16

-flagellum (plural, flagella)

-pilus (plural, pili)

Front 17

Flagellum (plural, flagellae)

Back 17

-a threadlike structure of protein fibers that extends from the cell surface

-may be one or many

-aids in locomotion and feeding

Front 18

pilus (plural, pili)

Back 18

-is a short flagellum

-aids in attaching to substrates and in exchanging genetic information between cells

Front 19

Eukaryotic Cells

Back 19

-Eukaryotic cells are larger and more complex than prokaryotic cells

have a plasma membrane encasing a cytoplasm

internal membranes form compartments called organelles

the cytoplasm is semi-fluid and contains a network of protein fibers that form a scaffold called a cytoskeleton

Front 20

Three types of protein fibers that composite cytoskeleton

Back 20

microtubules, microfilaments, and intermediate filaments

Front 21

microfilaments

Back 21

long, slender microfilaments made up of the protein actin

Front 22

microtubules

Back 22

hollow tubes made up of the protein tubulin

Front 23

intermediate filaments

Back 23

thick ropes of intertwined protein

Front 24

Centrioles

Back 24

-complex structures that assemble microtubules in animal cells and the cells of most protists

-they anchor locomotory structures, such as flagella or cilia

-they assemble microtubules and are usually located near the nuclear envelope

Front 25

Vacuoles

Back 25

are membrane-bounded storage centers

Front 26

central vacuole

Back 26

inside plant cells is filled with water and dissolved substances

Front 27

contractile vacuole

Back 27

found near the cell surface of some protists and accumulates excess water from inside the cell that it then pumps out

Front 28

Cell walls

Back 28

-found in plants, fungi, and many protists

-comprised of different components than prokaryotic cell walls

-function in providing protection, maintaining cell shape, and preventing excessive water loss/uptake

Front 29

Not all eukaryotic cells are alike

1. the cells of plants, fungi, and many protists have a beyond the plasma membrane

2. All plants and many protists contain organelles called?

3. Plants contain a?

4. animal cells contain?

Back 29

1. cell wall

2. Chloroplasts

3. central vacuole

4. centrioles

Front 30

nuclear envelope

Back 30

Double-membrane that binds the nuclear surface of the nucleus.

Front 31

Groups of proteins form openings here?

These groups allow RNA to pass in and out of the nucleus are called what?

Back 31

nuclear envelope

nuclear pores

Front 32

Nucleolus

Back 32

~The site for the subunits of the ribosome to be synthesizedt

~Dark-staining region of the nucleusit

-contains the genes that code for the rRNA (ribosomal RNA) that makes up the ribosomal subunits

-the subunits leave the nucleus via the nuclear pores and the final ribosome is assembled in the cytoplasm

Front 33

DNA of eukaryotes is packaged into segments and associated with a protein

Back 33

this complex is called a chromosome

Front 34

chromosome

Back 34

~The proteins enable the DNA to be wound tightly so it appears condensed

-the condensed or chromosome form of DNA occurs during cell division

Front 35

chromatin

Back 35

the DNA is uncoiled into strands called chromatin that are no longer visible as segments when the cell is not dividing

Front 36

protein synthesis occurs when

Back 36

he DNA is in the chromatin form

Front 37

The endoplasmic reticulum (ER)

Back 37

~An extensive system of internal membranes

~Some of the membranes form channels and interconnections

~Other portions become isolated spaces enclosed by membranes

-these spaces are known as vesicles

Front 38

rough ER

Back 38

The region of the ER dedicated to protein synthesis

-the surface of this region looks pebbly the rough

-spots are due to embedded ribosomes

Front 39

smooth ER

Back 39

The region of the ER that aids in the manufacture of carbohydrates and lipids

Front 40

The surface of this region looks smooth because it contains few to no embedded ribosomes

Back 40

smooth ER

Front 41

Golgi Apparatus

Back 41

function is to collect, package, and distribute molecules manufactured in the cell

Front 42

After synthesis in the ER, newly-made molecules pass to the

Back 42

Golgi bodies which are flattened stacks of membranes scattered throughout the cellcollectively called the Golgi complex

Front 43

The ER and Golgi complex function together as a

Back 43

transport system in the cell

Front 44

Golgi complex also gives rise to

Back 44

lysosomes

Front 45

lysosomes

Back 45

-membrane-bound structures that contain enzymes that break down macromolecules and old cell components

-worn-out cell parts are broken down and their components recycled to form new parts

-particles that the cell has ingested are also digested

Front 46

Peroxisomes

Back 46

are vesicles that isolate certain types of chemical reactions

Front 47

Peroxisomes

Back 47

the reactions that are confined to these organelles function to

1. Detoxify harmful by-products of metabolism

2. Convert fats to carbohydrates in plants seeds for growth

Front 48

Organelles That Contain DNA

Back 48

Eukaryotic cells contain cell-like organelles that, besides the nucleus, also contain DNA

-they include the following organelles: mitochondria and chloroplasts

Front 49

Mitochondria

Back 49

-cellular powerhouses

-Contain the chemical reactions called oxidative metabolism that extract energy from organic molecules

-Surrounded by two membranes

Front 50

Chloroplasts

Back 50

-are the sites for photosynthesis

-Also surrounded by two membranes

Front 51

Mitochondria and Chloroplasts

Back 51

-cannot be grown free of the cell

-they are totally dependent on the cells within which they occur

Front 52

Endosymbiont Theory

Back 52

-states that some organelles evolved from a symbiosis in which one cell of a prokaryotic species was engulfed by and lived inside of a cell of another species of prokaryote

-the engulfed species provided their hosts with advantages because of special metabolic activities

-the modern organelles of mitochondria and chloroplasts are believed to be found in the eukaryotic descendants of these endosymbiotic prokaryotes

Front 53

Evidence for Endosymbiont Theory

Back 53

-Both mitochondria and chloroplasts possess circular DNA that is not found elsewhere in the cellmitochondria are about the same size as modern bacteria

-The cristae in mitochondria resemble folded membranes in modern bacteria

Mitochondrial ribosomes are similar to modern, bacterial ribosomes in size and structure

-Mitochondria divide by fission, just like modern bacteria

-Thylakoid membranes within chloroplasts same as membranes within cyanobacteria

-Immune system responds to mitochondria the same as to bacteria

-Long-term antibiotic use damages cells because it damages mitochondria

Front 54

Cytoskeleton

Back 54

~Comprised of an internal framework of protein fibers that

-anchor organelles to fixed locations

-support the shape of the cell

-help organize ribosomes and enzymes needed for synthesis activities

Front 55

dynamic and its components are continually being rearranged

Back 55

The cytoskeleton

Front 56

Movement occurs across a biological membrane in one of three ways

Back 56

1. diffusionmembrane

2. foldingthrough

3. transport proteins

Front 57

Diffusion

Back 57

-Molecules tend to move from an area of higher concentration to an area of lower concentration

-ends when equilibrium is reached

Front 58

Water, although polar, is able to diffuse freely across the plasma membrane.

Back 58

True

-aquaporins are selective channels that permit water to cross

Front 59

Only certain substances undergo diffusion across the plasma membrane

Back 59

-molecules like oxygen, carbon dioxide, and non polar lipids

-ions and polar molecules cannot cross the interior of the membrane

Front 60

Osmosis

Back 60

Water moves down its concentration gradient when moving into or out of a cell

-the movement of water is dependent on the concentration of other substances in a solution

-the greater the amount of solutes that are dissolved in a solution, the lesser the amount of water molecules that are free to move

Front 61

The concentration of all molecules dissolved in a solution is called the of the solution?

Back 61

osmotic concentration

Front 62

osmotic pressure

Back 62

Movement of water by osmosis into a cell causes pressure

-enough pressure may cause a cell to swell and burst

-osmotic pressure explains why so many cell types are reinforced by cell walls

Front 63

Hypotonic
 solution

Back 63

-higher concentration of solute on the outside than on the inside.

-Water escaping the cell causes it to shrivel up.

Front 64

Isotonic 
solution

Back 64

-Water diffuses across a membrane but at the same rate in both directions.

-animals prefer

Front 65

Hypertonic
 solution

Back 65

-Pants prefer

-Water moves to dilute

-enters cell faster than it leaves

-higher concentration of solute on the inside than on the outside.

-cause cell to burst

Front 66

Organelles

Back 66

membrane enclosed structures within eukaryotic cells

Front 67

Tonicity

Back 67

the ability of a surrounding solution to cause a cell to gain or lose water

Front 68

Membrane Folding

Back 68

Bulky substances are contained within vesicles as they are moved into and out of a cell

-endocytosis

-exocytosis

Front 69

endocytosis

Back 69

is the engulfing of substances outside of the cell, forming a vesicle that brings the substances inside the cell

Front 70

Two types of Endocytosis

Back 70

1. Phagocytosis is endocytosis of particulate (solid) matter

2. Pinocytosis is endocytosis of liquid matter

Front 71

exocytosis

Back 71

is the discharge of substances from vesicles at the cell surface

Front 72

Selective permeability

Back 72

allows cells to control specifically what enters and leaves

involves using proteins in the membrane for transporting substances across

transport can be diffusion tractive transport

Front 73

Selective diffusion

Back 73

-proteins act as open channels for whatever is small enough to fit inside the channel

-this form of diffusion is common in ion transport

Front 74

Facilitated diffusion

Back 74

-proteins act as carriers that can bind only to specific molecules to transport

-transport is limited by the availability of carriers

-if there are not enough carriers, then the transport is saturated

Front 75

Active transport

Back 75

-utilizes protein channels that open only when energy is supplied

-energy is used to pump substances against or up their concentration gradients

-allows cells to maintain high or low concentration of certain molecules

Front 76

Compare and contrast facilitated diffusion and active transport

Back 76

Facilitated diffusion:

• Carrier protein required to move molecules

• no energy (passive) required

• Movement from high concentration to low concentration

Active Transport:

• Energy required to move molecules. ATP binds to the carrier protein and becomes ADP

• Molecules transported from low to high concentration

• Carrier protein required to move molecules

Front 77

Flattened membranes that process, package, and deliver proteins and lipids

Back 77

Golgi complex

Front 78

Name the subunits of carbohydrates, proteins, and nucleic acids

Back 78

monosaccharides, amino acids, nucleotide

Front 79

Contains digestive enzymes _________________

Back 79

lysosomes

Front 80

Contains the cell’s DNA _________________

Back 80

nucleus

Front 81

Site of protein synthesis

Back 81

Ribosomes

Front 82

Ribosomal DNA is synthesized the

Back 82

nucleolus

Front 83

Which organelle is responsible for the synthesis of lipids?

Back 83

smooth ER

Front 84

The site of cellular respiration in a eukaryote.

Back 84

mitochondria

Front 85

Mitochondria and chloroplasts contain their own DNA.

Back 85

True

Front 86

Which component of the the cytoskeleton is responsible for facilitating changes in cell shape?

Back 86

microtubules

Front 87

A molecule that is both hydrophobic and hydrophilic is called:

Back 87

amphipathic

Front 88

Membranes are static structures.

Back 88

False

Front 89

The movement of materials across a biological membrane that does not require the cell to expend energy.

Back 89

passive transport

Front 90

A cell placed into a hypertonic solution will

Back 90

lose water

Front 91

Both animals and plants use chemicals called _______ for long-distance signaling.

Back 91

hormones