CH. 4 WARM-UP
1.
At minimum, what structures or
components must a cell contain to be alive?
2.
What are the differences between plant and
animal cells?
3.
In biology, “Structure dictates function”.
Think of a type of cell in your body. In what
way is its structure related to its function?
Explain.
Assemble your Biochemistry Unit Packet in order (cover sheet on top). Staple or paperclip and turn into the basket. I will collect your tests and answer sheets.
WARM-UP
1.
Contrast prokaryotic vs. eukaryotic
cells.
2.
List and describe the contents
inside of the nucleus of a
eukaryotic cell.
3.
Describe the structure of the
WARM-UP
1.
Compare the diffusion times with
the SA:V ratio of the agar blocks.
Explain how the diffusion time and
SA:V ratio are related.
2.
Calculate your group’s Mass/Time
for your competition cube.
Compare with the other groups.
How effective was your group’s
cell design?
WARM-UP
1. The properties of several
artificial cells is shown in
the table. Which cell would
be the most efficient in
exchanging oxygen with the
environment by diffusion?
2. A certain human cell has a radius of 8 μm.
Calculate the surface area, volume, and the
SA:V ratio.
PRACTICE PROBLEM
Calculate the surface-area to volume ratio for these cells.
Which cell would likely be more efficient at
exchanging
substances with the surrounding
WARM-UP
1.
List 3 differences between plant and
animal cells.
2.
An antibody (a protein molecule) is
produced and released by a plasma cell.
List the pathway that this protein takes in
the cell from it’s production until it is
released to the outside of the cell.
(Hint:
The antibody travels through the
endomembrane system.)
3.
What would happen to a cell if it did not
CHAPTER 4
YOU MUST KNOW
Three differences between prokaryotic and eukaryotic cells.
The structure and function of organelles common to plant and animal cells.
The structure and function of organelles found only in plant cells or only in animal cells.
How different cell types show differences in subcellular components.
How internal membranes and organelles contribute to cell functions.
How cell size and shape affect the overall rate of nutrient intake and waste elimination.
2 TYPES OF CELLS:
1. Prokaryotes
: Domain Bacteria &
Archaea
2. Eukaryotes
(Domain Eukarya):
Protists, Fungi, Plants, Animals
PROKARYOTE VS.
EUKARYOTE
“ before”
“ kernel
”
No nucleus
DNA in a nucleoid
Cytosol
No organelles other
than ribosomes
Small size
Primitive
i.e. Bacteria &
Archaea
“ true”
“ kernel
”
Has nucleus and
nuclear envelope
Cytosol
Membrane-bound
organelles with
specialized
structure/function
Much larger in size
More complex
CELL SIZE AND SCALE
http://learn.genetics.utah.edu/content/begin/cells/ scale/
Scale of the Universe:
http://www.onemorelevel.com/game/scale_of_the_ universe_2012
Cells must be small to maintain a large
surface area to volume ratio
surface area to volume ratio
Large S.A. allows
rates of chemical
CALCULATE VOLUME OF A
SPHERE:
SURFACE AREA EXAMPLE (
ANIMAL
ANIMAL
):
Small Intestine
:
highly folded surface
to
increase absorption of nutrients
Villi
Villi
: finger-like projections on SI wall
Microvilli
Microvilli
: projections on each cell
Folds
SURFACE AREA EXAMPLE (
PLANT
PLANT
):
Root hairs
Root hairs
: extensions of root epidermal
cells; increase surface area for absorbing
water and minerals
NUCLEUS
Function: control center of cell Contains DNA (& mRNA)
Surrounded by double membrane (nuclear
envelope)
Continuous with the rough ER
Nuclear pores: control what enters/leaves
nucleus
Chromatin: complex of DNA + proteins; makes up
chromosomes
Nucleolus: region where ribosomal subunits (rRNA
RIBOSOMES
Function: protein synthesis Composed of rRNA + protein Large subunit + small subunit Types:
1. Free ribosomes: float in cytosol, produce
proteins used within cell
2. Bound ribosomes: attached to ER, make
ENDOMEMBRANE
SYSTEM:
Regulates protein traffic &
ENDOPLASMIC RETICULUM (ER)
Network of membranes and sacs Types:
1. Rough ER: ribosomes on surface
Function: package proteins for secretion,
send transport vesicles to Golgi, make replacement membrane
2. Smooth ER: no ribosomes on surface
Function: synthesize lipids, metabolize
ENDOPLASMIC RETICULUM
(ER)
GOLGI APPARATUS
Function: synthesis & packaging of materials (small
molecules) for transport (in vesicles); produce lysosomes
Series of flattened membrane sacs (cisternae)
Cis face: receives vesicles Trans face: ships vesicles
LYSOSOMES
Function: intracellular digestion; recycle cell’s
materials; programmed cell death (apoptosis)
VACUOLES
Function: storage of materials (food, water,
minerals, pigments, poisons)
Membrane-bound vesicles
Eg. food vacuoles, contractile vacuoles
Plants: large central vacuole -- stores water,
MITOCHONDRIA
Function: site of cellular respiration
Double membrane: outer and inner membrane Cristae: folds of inner membrane; contains
enzymes for ATP production; increased surface area to ATP made
CHLOROPLASTS
Function: site of photosynthesis Double membrane
Thylakoid disks in stacks (grana); stroma
(fluid)
Contains chlorophylls (pigments) for
ENDOSYMBIONT THEORY
Mitochondria & chloroplasts
share similar origin
Prokaryotic cells engulfed
by ancestors of eukaryotic cells
Evidence:
Double-membrane
structure
Have own ribosomes &
DNA
Reproduce
PEROXISOMES
Functions: break down fatty acids; detox
alcohol
Involves production of hydrogen peroxide
CYTOSKELETON
: NETWORK OF PROTEIN
FIBERS
Function: support, motility, regulate
PLANT CELLS
Cell wall: protect plant,
maintain shape
Composed of
cellulose
Plasmodesmata:
channels between cells to allow passage of
molecules from cell to cell
EXTRACELLULAR MATRIX
(ECM)
Outside plasma membrane of animal cells Composed of glycoproteins (ex. collagen)
Function: Strengthens tissues and transmits external
INTERCELLULAR JUNCTIONS
(ANIMAL CELLS)
Tight junctions: 2
cells are fused to form watertight seal
Desmosomes: “ rivet
s” that fasten adjacent cells into strong sheets
Gap junctions:
channels through which ions, sugar, small
Plant Cells Only Animals Cells Only Central vacuoles Lysosomes
Chloroplasts Centrioles
Cell wall of cellulose Flagella, cilia
Plasmodesmata Desmosomes, tight and gap junctions Extracellular matrix (ECM)
HARVARD CELL VIDEO
http://multimedia.mcb.harvard.edu/anim_inner life.html