Bio Chapter 4

Front 1

Surface area of a cell

Back 1

The surface area of a cell
is important for carrying
out the cell’s functions,
such as acquiring
adequate nutrients and
oxygen
-A small cell has more
surface area relative to
its cell volume and is
more efficient

Front 2

Most cells are small,
ranging from

Back 2

1 to 100
micrometers in
diameter

Front 3

Bacteria and archaea are

Back 3

prokaryotic cells

Front 4

Both prokaryotic and
eukaryotic cells have

Back 4

a
plasma membrane and one or
more chromosomes and
ribosomes

Front 5

Eukaryotic cells have

Back 5

a
membrane-bound nucleus
and a number of other
organelles, whereas
prokaryotes have a nucleoid
and no true organelles

Front 6

four life processes in eukaryotic cells

Back 6

Manufacturing
– Breakdown of molecules
– Energy processing
– Structural support, movement, and communication

Front 7

Manufacturing involves

Back 7

the
nucleus, ribosomes,
endoplasmic reticulum, and
Golgi apparatus
– Manufacture of a
protein, perhaps an
enzyme, involves all of
these

Front 8

Breakdown of molecules involves

Back 8

lysosomes,
vacuoles, and peroxisomes
– Breakdown of an
internalized bacterium
by a phagocytic cell
would involve all of
these
– Lysosomes, vacuoles,
and peroxisomes involve
digestion by hydrolytic
enzymes of unwanted
materials within the cell,
resulting in products
that are used by the cell
as food.

Front 9

Energy processing
involves

Back 9

mitochondria in
animal cells and
chloroplasts in plant
cells
Generation of energycontaining
molecules,
such as adenosine
triphosphate (ATP),
occurs in mitochondria
and chloroplasts

Front 10

Structural support,
movement, and
communication involve

Back 10

cytoskeleton, plasma
membrane, and cell wall
– An example of the
importance of these is
the response and
movement of phagocytic
cells to an infected area

Front 11

Structural support,
movement, and
communication involve the...

Back 11

Structural support,
movement, and
communication involve the
cytoskeleton, plasma
membrane, and cell wall

Front 12

Membranes within a eukaryotic cell partition the
cell into...

Back 12

Membranes within a eukaryotic cell partition the
cell into compartments, areas where cellular
metabolism occurs

Front 13

Each compartment is...

Back 13

fluid-filled and maintains
conditions that favor particular metabolic processes and
activities

Front 14

Although the cell is compartmentalized, none of the
cell’s components works alone.

Back 14

The cell is a living unit
greater than the sum of its parts.

Front 15

Although there are many
similarities between animal and
plant cells, differences exist

Back 15

-Lysosomes and centrioles are
not found in plant cells
-Plant cells have a rigid cell
wall, chloroplasts, and a
central vacuole not found in
animal cells

Front 16

The plasma membrane controls...

Back 16

The plasma membrane controls
the movement of molecules into
and out of the cell, a trait called
selective permeability

Front 17

Membranes are made of...

Back 17

Membranes are made of
lipids, proteins, and some
carbohydrate, but the most
abundant lipids are
phospholipids

Front 18

Structures of membranes correlates with their function

Back 18

-Phospholipids form a two-layer
sheet called a phospholipid
bilayer
-Thus, hydrophilic heads are
exposed to water, while
hydrophobic tails are shielded
from water
-Proteins are attached to the
surface, and some are embedded
into the phospholipid bilayer

Front 19

The nucleus controls...

Back 19

The nucleus controls the cell’s
activities and is responsible for
inheritance

Front 20

Inside the nucleus is ...

Back 20

Inside is a complex of
proteins and DNA called
chromatin, which makes up
the cell’s chromosomes
– DNA is copied within the
nucleus prior to cell division

Front 21

The nuclear envelope is...

Back 21

The nuclear envelope is a double membrane with pores
material to flow in and out of the nucleus
-It is attached to a network of
cellular membranes called the
endoplasmic reticulum

Front 22

Chromatin

Back 22

Consist of DNA and proteins

Front 23

The genes on the DNA provide..

Back 23

The genes on the DNA provide
a blue-print to make proteins
which are needed by the cell

Front 24

Nucleolus

Front 25

Ribosomes are...

Back 25

Ribosomes are involved in the
cell’s protein synthesis
– Ribosomes are synthesized
in the nucleolus, which is
found in the nucleus
– Cells that must synthesize
large amounts of protein
have a large number of
ribosomes

Front 26

Free ribosomes are...

Back 26

Free ribosomes are
suspended in the cytoplasm

Front 27

Bound ribosomes are...

Back 27

Bound ribosomes are
attached to the endoplasmic
reticulum (ER) associated
with the nuclear envelope

Front 28

endomembrane system

Back 28

The membranes within a
eukaryotic cell are physically
connected and compose the
endomembrane system
– The endomembrane system
includes the nuclear
envelope, endoplasmic
reticulum (ER), Golgi
apparatus, lysosomes,
vacuoles, and the plasma
membrane

Front 29

In general, the endomembrane system
regulates

Front 30

vesicles

Back 30

Some components of the
endomembrane system are
able to communicate with
others with formation and
transfer of small membrane
segments called vesicles
– One important result of
communication is the
synthesis, storage, and
export of molecules

Front 31

The endoplasmic reticulum is a biosynthetic
factory

Front 32

Smooth ER is involved in a variety
of diverse metabolic processes

Back 32

– For example, enzymes
produced by the smooth ER
are involved in the synthesis
of lipids, oils, phospholipids,
and steroids
– Cells of the ovaries and testes
synthesize the steroid sex
hormones. These cells are
rich in Smooth ER;
– Liver also has large amts of
SER with additional types of
functions*

Front 33

Liver also has large amts of
SER with additional types of
functions*

Back 33

– Certain enzymes in the
smooth ER of the liver cells
helps process drugs and
harmful substances eg.
Barbiturates
– Complication: 1 As the cell
are exposed to such
chemicals, the amount of
smooth ER and its detox.
enzyme increase, thereby
increasing the rate of
detoxification and thus the
body’s tolerance to drugs
– Complication 2: detoxifying enzymes
can not distinguish among related
chemicals
– As a result, the growth of the SER in
response to one drug can increase
tolerance to other drugs e.g.
important medicines

Front 34

SER – store...

Back 34

SER – stores calcium ions e.g. in
muscles the SER pumps calcium into
the interior of the ER which allows
muscle contraction

Front 35

Rough ER makes additional
membrane for itself and proteins
destined for secretion

Back 35

Note: proteins are synthesized
by the ribosomes found on the
RER
– Once proteins are synthesized,
they are transported in
vesicles to other parts of the
endomembrane system
– An example of a secretary
protein = insulin, a hormone
secreted by certain cells in the
pancreas

Front 36

The Golgi apparatus finishes, sorts, and ships
cell products

Back 36

The Golgi apparatus functions in
conjunction with the ER by
modifying products of the ER
– Products travel in transport
vesicles from the ER to the
Golgi apparatus
– One side of the Golgi
apparatus functions as a
receiving dock for the product
and the other as a shipping
dock
– Products are modified
as they go from one
side of the Golgi
apparatus to the other
and travel in vesicles
to other sites

Front 37

Lysosomes are digestive compartments
within a cell

Back 37

A lysosome is a membranous
sac containing digestive
enzymes
– The enzymes and
membrane (the
lysosomes) are produced
by the ER and transferred
to the Golgi apparatus for
processing
– The membrane serves to
safely isolate these potent
enzymes from the rest of
the cell

Front 38

One of the several functions of lysosomes is to

Back 38

One of the several functions of lysosomes is to
remove or recycle damaged parts of a cell
– The damaged organelle is first enclosed in a membrane
vesicle
– Then a lysosome fuses with the vesicle, dismantling its
contents and breaking down the damaged organelle

Front 39

Vacuoles function in the general maintenance
of the cell

Back 39

Vacuoles are membranous
sacs that are found in a
variety of cells and possess
an assortment of functions
– Examples are the central
vacuole in plants with
hydrolytic functions,
pigment vacuoles in
plants to provide color to
flowers, and contractile
vacuoles in some protists
to expel water from the
cell

Front 40

Cellular respiration is accomplished in...

Back 40

Cellular respiration is accomplished in
the mitochondria of eukaryotic cells
– Cellular respiration involves
conversion of chemical energy in
foods to chemical energy in ATP
(adenosine triphosphate)

Front 41

Mitochondria have two internal
compartments

Back 41

The intermembrane
space, which encloses
the mitochondrial
matrix where materials
necessary for ATP
generation are found

Front 42

Chloroplasts

Back 42

Chloroplasts are the
photosynthesizing organelles of
plants
– Photosynthesis is the
conversion of light energy to
chemical energy of sugar
molecules

Front 43

Chloroplasts are partitioned into
compartments

Back 43

The important parts of
chloroplasts are the stroma,
thylakoids, and grana

Front 44

Mitochondria and chloroplasts evolved by
endosymbiosis*

Back 44

When compared, you find that mitochondria and
chloroplasts have (1) DNA and (2) ribosomes
– The structure of both DNA and ribosomes is very similar
to that found in prokaryotic cells, and mitochondria and
chloroplasts replicate much like prokaryotes

Front 45

The hypothesis of endosymbiosis

Back 45

The hypothesis of endosymbiosis proposes that
mitochondria and chloroplasts were formerly small
prokaryotes that began living within larger cells
– Symbiosis benefited both cell types

Front 46

Cells contain a network of

Back 46

Cells contain a network of protein fibers, called the
cytoskeleton, that functions in cell structural
support and motility
– Scientists believe that motility and cellular regulation
result when the cytoskeleton interacts with proteins
called motor proteins

Front 47

The cytoskeleton is composed of three kinds of fibers

Back 47

– Microfilaments (actin filaments) support the cell’s shape and are
involved in motility
– Intermediate filaments reinforce cell shape and anchor
organelles
– Microtubules (made of tubulin) shape the cell and act as tracks
for motor protein

Front 48

Cilia and flagella move when microtubules
bend

Back 48

While some protists have
flagella and cilia that are
important in locomotion, some
cells of multicellular organisms
have them for different
reasons
– Cells that sweep mucus
out of our lungs have cilia
– Animal sperm are
flagellated

Front 49

flagellum propels a cell by

Back 49

A flagellum propels a cell by
an undulating, whiplike
motion

Front 50

Cilia

Back 50

work more
like the oars of a crew boat

Front 51

Both flagella and cilia are made of...

Back 51

Both flagella and cilia are made of
microtubules wrapped in an
extension of the plasma
membrane

Front 52

Cilia and flagella move by...

Back 52

Cilia and flagella move by
bending motor proteins called
dynein arms
– These attach to and exert a
sliding force on an adjacent
doublet
– The arms then release and
reattach a little further along
and repeat this time after
time
– This “walking” causes the
microtubules to bend

Front 53

genetic reasons that
sperm lack motility

Back 53

Primary ciliary dyskinesia (PCD) is an example
– PCD is a rare disease in which there is an absence of
dynein arms, which prevents microtubules from
bending.

Front 54

decline in sperm quality

Back 54

A group of chemicals c g oup o a alled phthalates used in a variety
of things people use every day may be the cause

Front 55

extracellular matrix (ECM)

Back 55

essential to cell function
– The ECM is composed of
strong fibers of collagen,
which holds cells together
and protects the plasma
membrane
– ECM attaches through
connecting proteins that
bind to membrane proteins
called integrins

Front 56

Integrins

Back 56

Integrins span the
plasma membrane
and connect to
microfilaments of the
cytoskeleton

Front 57

Three types of cell junctions are found in
animal tissues

Back 57

– Tight junctions
– Anchoring junctions
– Gap junctions

Front 58

Adjacent cells communicate,
interact, and adhere through

Back 58

specialized junctions between
them

Front 59

Tight junctions

Back 59

forms a
seal that prevent leakage of
extracellular fluid across a
layer of epithelial cells (like a
zipper-lock seal in bags)

Front 60

Anchoring junctions

Back 60

fasten
cells together into sheets

Front 61

Gap junctions

Back 61

are channels
that allow molecules to flow
between cells

Front 62

Plant cells have cell junctions called

Back 62

Plant cells have cell junctions called
plasmodesmata that serve in communication
between cells