1. Chapter 7: Cell Structure & Function
Section 2: Cell Structure

2. Structure & Support Cell Membrane:
the cell’s outer boundary, acts as a barrier between the outside environment.
outer, protective layer of the cell
controls how easily things can pass in and out of the cell
The cell membrane is “selectively permeable” which means that it only lets certain things in and out of the cell
Sometimes called the plasma membrane
Made of Phospholipids which form a lipid bilayer
Hydrophilic Heads: “Water Loving” face outside and inside the cell
Hydrophobic Tails: “Water Fearing” inside of the bilayer

3. Cell Membrane

4. Cell Wall: found mainly in plant cells, support and protect the cell
made up of cellulose, which is a carbohydrate
Found in prokaryotes (bacteria), protists, fungi, and plants
Most cell walls are porous enough to allow water, oxygen, and carbon dioxide to pass through them and get into the cell

5. Cytoplasm:
Fluid or jelly-like substance inside the cell and almost all structures in the cell that are suspended in it
similar to broth in a pot of soup

6. Cellular Activity Nucleus:
Found only in eukaryotic cell, and contains DNA
If found in a cell it immediately indicated a eukaryote
control center of the cell; directs cellular activity; stored heredity information
“brain of the cell”
Nucleolus: ribosome parts are made here; interior part of nucleus
Nuclear Envelope: double membrane surrounding nucleus

7. Molecule that stores genetic information used to make proteins
DNA:
Molecule that stores genetic information used to make proteins
in the Nucleus
double helix shape
Made of:
Phosphate Group
5 carbon sugar; deoxyribose
Nitrogenous bases: adenine, thymine, guanine, and cytosine

8. Ribosomes:
place where proteins and enzymes (speed up bodies chemical reactions) are made/synthesized by following the instructions that come from DNA
Made of proteins and RNA
There are 2 types of ribosomes:
Free Ribosomes: can be found floating in the cytoplasm
Bound Ribosomes: can also be found attached to the membrane an organelle
Example: the rough endoplasmic reticulum has ribosomes bound to it’s membrane and help make proteins

9. Protein Packaging Endoplasmic Reticulum (ER):
a system of internal membranes that aids in the production, processing, and transport of proteins and lipids (fats) through the cell
Rough ER: ribosomes are attached to endoplasmic reticulum, proteins are made here; produce vesicles filled with proteins
Smooth ER: no ribosomes on endoplasmic reticulum, makes lipids; produce vesicles filled with lipids

10. Golgi Apparatus:
process, package, and secrete substances to the outside of the cell
Modifies, sorts, and packages proteins for distribution throughout the cell and for export
considered the “UPS” of the cell

11. Storage & Maintenance Lysosome:
small, spherical structures that contain enzymes
breakdown and digest molecules like carbohydrates, proteins, fats, and DNA & RNA
Digest damaged organelles & foreign substances
“Garbage Man” of the cell

12. Storage & Maintenance Vesicle
Membrane bound sac that buds off of other organelles
Joins/fuses with other organelles
Store, transport, and digest cellular particles & waste
Examples:
Vesicles bud off of the ER and store proteins and lipids to be used within the cell or transported to other organelles
Vesicles can join/fuse with the lysosome to deliver particles that need to be digested

13. Vacuole: membrane bound sac used for storage of water, waste, & nutrients
larger and more common in plant cells; Central Vacuole
example: cacti have a large vacuoles for storing water.

14. Energy Production
Mitochondria: place where cellular respiration occurs
where most of a cell’s ATP is made – made in the inner membrane
Adenosine Triphosphate (ATP): compound used by cells to store and release energy
called the “powerhouse” of the cell
Cells that require/need a lot of energy have more mitochondria than cells that do not require/need as much energy
found in plant and animal cells
has its own DNA

15. Chloroplast: found in plant cells only, site/place where photosynthesis occurs
converts energy from the sunlight into chemical energy (sugars) using carbon dioxide & water
contains its own DNA and ribosomes
Reason plants are green

16. Movement Structures
Cytoskeleton:
a web of protein fibers
Supports the cell like bones support your body
Helps the cell move, keep its shape, & organize its parts

17. Movement Structures
3 types of cytoskeleton fibers:
Microfilaments:
long, thin fibers that are made of protein actin
Some attach to the cell membrane
Contract to pull the membrane in some places & expand to push it out in others

18. Movement Structures
Intermediate Fibers:
Moderately thick & mainly anchor organelles & enzymes to certain parts of the cell

19. Movement Structures
Microtubules:
Thick, hallow fibers that are made of protein tubulin
Information molecules move through these tubes to various parts of the cell

20. Cytoskeleton

21. In these cells, microfilaments appear light purple, microtubules yellow, and nuclei greenish blue. ↓
↑ The three fibers of the cytoskeleton: microtubules in blue, intermediate filaments in red, and microfilaments in green–play countless roles in the cell.

22. Movement Structures
Centrioles – help pull the chromosomes (DNA) apart when the cell divides and reproduces (contain microtubules)

23. Movement Structures
Flagella: long, Whip-like extension that help the cell move (contain microtubules)
usually only one flagella on a cell
example: sperm cell
Cilia: short hair-like extensions that help the cell move (contain microtubules)
there are hundreds of cilia on each cell

24. Diversity in Cells Diversity in Prokaryotes: Vary in shape
Way they obtain energy
Makeup of the cell walls
Ability to move
Flagella; to move quickly
Pili: short, thick outgrowths that allow them to attach to surfaces and other cells

25. Diversity in Eukaryotes
Plants:
Chloroplasts
Large central vacuole
Cell wall that surrounds the cell membrane
Vary structure by function
Some organelles are more prominent in specialized cells
Varying internal makeup can allow cells to be specialized for specific functions
Example: muscle cells have lots of mitochondria bc muscles require a lot of energy

26. Prokaryote vs Eukaryote

27. Animal Cell

28. Plant Cell

29. Plant cell vs Animal cell

30. Levels of Organization
Cells:
the smallest unit that can carry on all of the processes of life
A group of cells that are organized and working together make up tissues.

31. Tissues:
a distinct group of cells that have similar structures and functions
Ex: muscle tissue is group of many cells that have bundles of cytoskeletal structures.
A group of tissues working together make up organs.

32. Organ:
different types of tissues arranged so that specialized functions can be carried on.
Ex: Lungs being able to pump oxygen in and out to the rest of your body.
A group of organs working together make up organ systems

33. Organ Systems: various organs that carry out a major body functions.
Ex: Respiratory System major function is the uptake of oxygen into our bodies.

34. Cells → Tissues → Organs → Organ Systems

35. Body Types
Sometimes, entire body of an organism is made up of a single cell
Cell must carry out all of the activities
Growing
Using energy
Responding to the environment
Reproducing
More than half of the biomass on earth is composed of unicellular organisms
Single cells cannot grow larger than a certain size

36. Multicellular organisms are composed of many individual, permanently associated cells that coordinate their activities
Distinct types of cells have specialized function
Individual cells cannot survive alone and are dependent on the other cells of the organism

37. Cell Groups
Some unicellular thrive independently, but others live in groups
Colonial organisms:
Cells that live as a connected group but DO NOT depend on each other for survival
Example: cell walls of some bacteria adhere to one another after dividing, but can survive independently

38. Multicellularity Only in Eukaryotes
Cells in a multicellular body perform highly specific functions
Some cells protect organisms from disease & predators
Some cells help with movement, feeding, & reproduction
Most multicellular organisms begin as a single cell
Example: a chicken starts as an egg; new cells form from cell division; cells grow & undergo differentiation(process of developing specialized forms & functions); specialized cells arrange into tissues, organs, & organ systems to make the entire chicken