August 25-26, 2014
What do these all have in common?
Real cells differ greatly from
each other and from a
‘generalized cell’ in order to
carry out different functions.
Cells differ in:
• Size
• Shape
• Number & type of
organelles
How well do you remember the structures of
the cell?
Earn bragging rights by being the first to
match up the structure with the function.
Afterwards, use the same papers to label a
generalized cell diagram.
With a partner, answer the 4 questions on your
guided notes.
… 5 minutes
Identify special features of each cell that help
them do their specific functions.
What special
features do you see?
What special
features do you see?
- Microvilli to
increase surface
area for
absorption of
nutrients
- Tight junctions
between cells to
prevent digestive
enzymes from
leaking into the
tissue of the small
intestine.
What special
features do you see?
What special
features do you see?
- Small to fit
through capillaries
- No organelles or
nucleus to
maximize area for
carrying oxygen
What special feature do you see?
What special feature do you see?
cilia – to help move mucus over
surface of the trachea
What is the difference between microvilli and cilia?
What is the difference between microvilli and cilia?
- Microvilli are extensions of cell membrane, cilia are
proteins
- Microvilli increase SA for absorption, cilia move
substances
Read your textbook for more examples!

Selectively permeable barrier between the cell
and the environment.
What does ‘selectively permeable’ mean?
Only some materials can cross the
membrane
Selective permeability is necessary for the
cell to maintain the correct internal
environment for physiological functions.

Phospholipids
◦ Make up the majority of
the membrane
◦ Arranged in a bilayer,
with hydrophilic heads
outside, and
hydrophobic tails inside
Hydrophilic = ___________
Hydrophilic molecules are __________ like water.
Hydrophobic = ____________
Hydrophobic molecules are __________ like oil.

Phospholipids
◦ Make up the majority of
the membrane
◦ Arranged in a bilayer,
with hydrophilic heads
outside, and
hydrophobic tails inside
Hydrophilic = water loving
Hydrophilic molecules are polar like water.
Hydrophobic = water fearing
Hydrophobic molecules are nonpolar like oil.

Phospholipids
The structure of
phospholipids is the key
to their function!
Hydrophilic heads can interact with watery external
environment and watery cytoplasm.
Hydrophobic tails reduce the diffusion of water and
other charged or polar substances across the
membrane.

Cholesterol
◦ Makes the cell membrane more rigid
and less permeable to water

Proteins
◦ Act as enzymes, pores, carriers, and hormone
receptors, and structural elements

Glycoproteins and Glycolipids
◦ Glyco = sugar!
◦ Influence cell interactions (e.g. identifying cell as
‘self’) and molecule transport
Talk with a partner then share as a class

Scholar on the left answers …
◦ What are the 4 membrane components?
◦ Which component has most functions? Why?

Scholar on the right answers …
◦ Name 4 functions of membrane proteins
◦ Which two components are primarily responsible for
reducing fluid loss through the cell? What do those
components have in common?
For each sheet,
 The vocabulary word(s) and definition(s)
should be written in large letters
 A diagram should be drawn.
Must be accurate, neat, and visually appealing!
Vocab minisheets / Study!




What were our objectives and how well did you
learn about them?
How did what we do today connect to our unit
statements?
What learner profile trait did we demonstrate?
TOK connection: What are the primary ‘ways of
knowing’ that lead to our scientific knowledge of
cells?
Draw and label a cell. At least 5 of the
components should be labeled with name and
function.