Campbell Reece Biology
Chapter 7
A Tour of the Cell
The cell is to biology as the a_____ is to chemistry. The cell is the simplest colle t of
matter that can l_____.
Life at a cellular level arises from s________ order, reinforcing the themes
of e_________ p_________ and the correlation between s__________ and
f__________.
We know about cells because of the invention in the ____th
century of the m________. The
first were the LMs (l_______ m______).
The two important factors in micrsopy are magnification (the ratio of
the image to its r_____ s_____).
R_______ power is a measure of the clarity of the image, how fuzzy
something will be.
The R______ power of the human e_____ and of m________ is
limited. Light microscopes can’t
resolve finer than .2 micrometers, the size of a small b_______, because it is
limited by the length of a w____ of l_____. They can magnify ______ times, but the image may be blurry.
Subcellular structures, the parts of a cell, are called
o________. They usually have to be
studied using an EM (e______ m_______) .
110-111
The two kinds of electron microscopes are the TEM
(t__________ electron microscope) and the SEM (s_____ electron
microscope). The SEM studies the
s________, the TEM the internal structure.
Sometimes the specimen needs to be sectioned, taking a
th_____ sl_____; and sometimes it is d______ed for better contrast.
C________ is the study of cell structure; b_________ is the study of moelcules
and chemical processes of metabolism.
Cell fractionation means to take the cells a______. U______ spin at the rate of 130,0000
revolutions per minute (rpm) and apply a force to separate the particles that
is more than one million times the force of g____________.
Homogenization breaks the cell apart without damaging the
or_______, its done by spinning slowly until the cell soup breaks into a p_____
(the heavier, larger parts) and the s_____ (the lighter parts). The heavy parts sink to the bottom, and
the lighter parts are decanted off and the process is re_______.
112-113
Draw the prokaryotic cell on page 112
All cells are bound by a p_________ m_________, and within
this is a semifluid substance called c____________ in which organelles are
found. All contain genes in the
form of D____ and all have r______ to make pr_______ following the
instructions.
The two kinds of cells are pr_____________ and
e__________. E_________ cells have
a membrane bound n____________, pro_______________ have an area with the DNA in
it but there is no m_____________ around its n_________d.
The region between the nucleus and the plasma membrane is
the c______.
E___________ cells are usually bigger than p_________
cells; they are usually about ten
times as large as b_____________ cells.
Cells can only get so large because of the ratio between the
volume and the s______ ar_____.
The plasma membrane is a selective barrier – it only lets in
and out certain things.
Larger organisms usually don’t have larger cells, they have
m_____ cells.
114 – 115
Separate project – draw in detail the animal and plant cells
on these pages.
Membranes usually are made up of a double layer of
ph_________, with pr_______ embedded.
116-117
Separate project,
draw in detail the nucleus and the ribosomes
The nuclear envelope is a d______ membrane, separated by a
small space. The nuclear
l_________ is a net of proteins that maintain the structure of the nucleus, and
the p_____ complex allows movement in and out.
The fibrous material in the nucleus is the ch_______. As the cell begins to reproduce, this
coils up and separate structures, called ch_______ emerge.
Each eukaryotic species has a distinct number of
ch_________. A human cell has
______. The egg and sperm human
cells, though, have only _____ each, becuase they combine to make a complete
set.
The RNA to makes ribosomes and m______ RNA are made in the
nucleus and sent out through the p________.
Ribosomes make __________ using the R_______ code copied
from the D_____ in the nu_______.
118-119
Ribosomes (and nucleoili) aren’t bound by m_________.
Free ribosomes are suspended in the c_______, bound
ribosomes are attached to the ER (en______ re_______) or the nuclear
envelope. They make pr_________
for different places.
The endo_________ system is the system of membranes that are
touching or that transfer using ve_______ (membranes bound sacs that get
absorbed into other membranes).
The ER (e___________ r____________) is a membranous
labyrinth, more than half the total membrane in a eukarytoic cell is in the
ER. The membrane separates the
ER’s ci_______ from the cytosol, and it is continuous with the nuclear
envelope, so the ci______ space connects with the nuclear envelope.
S______ ER doesn’t have r_____, R_________ ER does.
separate project, draw the ER
Sm______ ER makes li________, metabolizes ca_______, and
detoxes drugs and poisons.
The ER makes st_____, including s_____ and adre_______
hormones; an enzyme in the ER of
l________ cells helps the liver store and release glu_______.
ER usually detoxifies poisons by adding a h______ group to
make them more s__________ and easier to flush out.
Some drugs (like alcohol) actually make cells create more
ER, so that you need more of the drug next time to get the same effect, it
creates drug resistance to that drug and sometimes to others.
ER and calcium work together to make m____________ contract.
Transport v_______ move substances without letting them mix.
The ER makes m_______ for itself and can make it and
transfer it to other parts of the cell using tr_______ v_________.
The G_________a_________ is a center of ma________,
w__________, s___________ and sh___________. Products from the ___________ are sent here and sorted
before being sent out to other areas.
120—121
separate project, draw Golgi apparatus p. 120
The Golgi apparatus looks like s______ of pita bread. V_______ move in and out of it.
The two ends of the stack are different, there is a c____
face and a tr______ face, one receives and one ships out. The c____ face is near the E_______,
the tr_______ face gives rise to v_________ that pinch off and travel to other
sites.
The Golgi apparatus alters products as they move
through; it might alter a protein
by adding or removing mo_________.
It also manufactures some m__________.
The Golgi will put a t____ on a product that is recognized
at d______ sites on other organelles or the plasma membrane so the products go
to the right places.
separate project, draw a lysosome (easy)
A lysosome is m______ bound, full of en________, and used to
digest ma____________ like polysacharides, fats, proteins, nd nucleic
acids. The enzymes work best in
a______ environments (like our stomach digests things best in ac_____), with a
pH of ____. It keeps a low pH by
pumping h______ inons from the cytosol outside into the lysosome. If it breaks open or leaks, the
en________ aren’t very dangerous because they are slowed down in the higher pH
(neutral, about ______) of the cytosol.
If too much leaks, though, it can destroy a cell – it d______ itself
from the inside.
Some amoebas and protists eat using just their lysosomes, no
stomachs. They engulf a food
particle or organism (ph__________), then the food vacuole merges with a
lysosome and the enzymes digest it.
The digested products pass out into the cytosol for use by the
cell. Some human cells, like
m________, also engulf and destroy.
This is part of the human i_______ system, killing b__________.
A human cell will use a lysosome to take apart its old parts
into pieces that it will then use to make new parts – the liver will recycle
half its macromolecules each week.
122-123
Lysosomes in a tadpole destroy the cells of its t_____, and
lysomes digest the w______ between the fingers of human emb____________.
Lysosomal disorders can be dangerous diseases. Pompe’s disease damages the l______
because the lysomes cannot break down the gl________. In T_________ disease, the brain is damaged by l________ the
lysosomes don’t break down.
V______ and v_______ are both membrane bound sacks, but
v_____ are bigger. Some protists
use vacuoles filled with w________
that can con_____. Plants
usually have a large ce________ vacuole with sa_____ in it. This stores compounds and ions like
p______ and ch________; they use
the vacuole to dispose of by__________ or hold p_________. They sometimes contain compounds that
are p________ or taste bad to discourage predators.
separate project, draw a vacuole (easy)
Organisms are o_____ systems.
124—125
separate project, draw a mitochondrion
Mitochondria are the sties of cellular r__________. That’s a ca______ process that
generates A______ by extracting energy from s______, f______ and other fuels
with the help of o_________.
Chloroplasts are only in plants and algae, and are the sites of
ph____________, changing s_______ energy into che___________ energy and using
c_________ d________ and w_________.
These organelles are a little different and independent
because their membranes are made by ribsomes, not hte ER, and they have a
little D_____ and re______ in the cell.
Mitochondria are in almost all eu_____ cells, a cell might
have one or th______, depending on how much met______ activity there is. The m____, change sh____, and di______.
It has a double membrane of ph_____ with embedded pr_____.
The inner membrane is folded up into cristae; the m______ is where cellular
respiration occurs, the large s______ area enhances this.
A choloroplast is a kind of p______. They contain the green pigment
ch__________ and are found int he gr_______ parts of plants and algae.
Th________ in a chloroplast are piled in stacks called
g________ and surrounded by fluid called the s___________. Chloroplasts change sh_________, they
gr________, and can pinch in two to re___________. They m________.
separate project, draw a choloroplast
A pe____________makes hydrogen peroxide, they transfer
hydrogen.
126 – 127
The c________________ of a cell gives it support and shape,
like the skeleton of an animal. It
is used in cell mo________, movement.
Proteins called m_______ molecules assist motility.
The motor molecules of the cytoskeleton can move the c_____
and fl__________ or cause m______ cells to contract; they can transport v____ long their “rails”; they form the vacuoles that engulf in
phago_________ and stream the cyto_________.
They cytoskeleton contains m___________ (thickest),
in______________ f________ (medium thickness) and mi__________ (thinnest
filaments).
128-129
C__________ and c______________ take part in creating
microtubules.
F_________ and c__________ stick out from the cell to move
the cell or to move things along the outside of the cell. You have c________ inside your windpipe
to move m_______ containing debris out of your lungs.
There’s usually just one or two f___________, but often many
c_________. F______ move like a
mermaid tail, while c_____ move more like oars.
They usually share the same structure of microt__________.
130—131
The d_______ protein in a cilia moves by attaching and pulling, like a cat
pulling itself up a tree. Protein
tensions facilitate cell contractions.
Actin and myosin play a role in amoebas extending
pseudopodia, false f_____. White
blood cells also cr_____ like amoebas by pushing and pulling cystoplasm. In plant cells, the cytoplasm
str________.
132—133
Plant cells have cell w______, animal cells don’t.
They protect the plant, hold the sh______, and stop the
plant from pulling in too much w________.
They help the plant stand up against the pull of g________. They are thick and contain
c_______ose.
A young plant first secretes a thin wall called a pr_______
cell wall. The m______ l________
is made up of sticky pe_______ and glues the cell together (p_____ is used in
jams). It strengthens the wall
after it’s grown by either secreting a h________ substane or creating a
s________ cell wall. W______ is
made up of cell wall.
Between the cells of animals are glycoproteins, usually
co______, which forms fibers outside the cells. Half the pr________ in the human body is co________, so
there’s a lot of it.
The extracellular matrix can help communication between
cells.
Cells are organized into t_______, then or______, then
or________ sy__________.
Cytosol from one cell can travel through a plasmodesmata to
another cell.
Cells demonstrate the biological feature that str________ is
connected to f______, and shows the “whole is greater than the sum of its
parts” factor we call em_______ pr___________.
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