1. Cell Organelles
Wakefield
2016

2. Cells Robert Hooke discovered the cell in the late 1600’s
The smallest part of any living organism
Contains all parts necessary to survive in changing environments

3. Macromolecule Structure
Cells
Made primarily of H, O, C, & N
Though it also needs trace elements
Contains about 60% water
Intracellular and Interstitial
Main solid consists mainly of proteins
Macromolecule Structure
Carbohydrate – C, H, O
Protein – C, H, O, N
Lipid – C, H, O, P
Nucleic Acids – C, H, O, N
Water – H, O

4. Cells Cells are very diverse Vary in length
2 micrometers to more than 3 feet
Structure defines in function which are also very diverse

5. Prokaryotic Cells vs. Eukaryotic Cells
All cells have generalized features:
Cytosol – semi-liquid fluid in which organelles are suspended – found in both pro & eukaryotic cells
Organelles – small organs of cell – most found only eukaryotic cells
Plasma Membrane – double layer of phospholipids which surrounds cell – found in both pro & eukaryotic cells
Inclusions – Non-functioning parts of cell

7. NUCLEUS – CONTROL CENTER
Located near the center of the cell
Found in both plants & animals
Found only in eukaryotic cells
Contains the organism’s genetic material
The cell (and organism’s) “blueprint”
DNA – Deoxyribonucleic Acid
Chromatin
Genes
Chromosomes

8. NUCLEOLUS – 1 OR MORE SMALL BODIES IN CENTRAL AREA OF NUCLEUS
Located near the center of nucleus
Found in both plants & animals
Found only in eukaryotic cells
Site for ribosome production which will migrate to cytoplasm

9. NUCLEAR ENVELOPE – (aka) NUCLEAR MEMBRANE
Located surrounding the nucleus
Found in both plants & animals
Found only in eukaryotic cells
Consists of a double-layer selectively permeable membrane with relatively large pores (nuclear pores)
Serves to protect the nucleus and determines what enters & leaves nucleus

10. CHROMATIN– DNA (when it is not dividing)
Located inside the nucleus
Found in both plants & animals
Found only in both prokaryotic and eukaryotic cells – just not within a membrane bound nucleus
Consists of DNA (Genetic Material)
Appears as loose bumpy granular material scattered throughout the nucleus

11. CHROMOSOME – DNA (when it is dividing)
Located inside the nucleus
Found in both plants & animals
Found in both prokaryotic & eukaryotic cells
Consists of DNA (Genetic Material)
Appears as shortened thick structures resembling X’s or curved lines – condensed chromatin material

12. CHROMASOME – CONDENSED CHROMATIN / DNA

13. PLASMA MEMBRANE – (aka) CELL MEMBRANE
Surrounds the outside of the cell’s cytoplasm
Found in both plants & animals
Found only in eukaryotic cells & prokaryotic cells
Consists of phospholipid bi-layer
Functions to determine what enters and leaves the cell – is selectively permeable – selects which materials can pass across the membrane

14. PLASMA MEMBRANE – (aka) CELL MEMBRANE
Specializations –
Microvilli – tiny fingerlike projections that greatly increase the cell’s surface area
Enhances cell’s absorption ability
Small intestines

15. PLASMA MEMBRANE – (aka) CELL MEMBRANE
Specializations –
Membrane Junctions – varies structurally
Tight Junctions
Impermeable
Bind cells together like a zipper
Desmosomes
Anchoring junctions which prevent cells from tearing apart (i.e. – skin to skin or skin to muscle)

16. PLASMA MEMBRANE – (aka) CELL MEMBRANE
Specializations –
Membrane Junctions – varies structurally
Gap Junctions
Connects adjacent cells with tubular connexons which look like hollow cylinders
Found in the heart, embryonic cells
Functions mainly in cell to cell communication

17. Plasmodesmata – Eukaryote / Plants
Sites for inter-cytoplasmic communication in plants
Similar to Gap Junctions in Animal Cells

18. Nuclear Lamina – Eukaryote / Plants & Animals
Inter-nuclear network of intermediate filaments and proteins providing mechanical support

19. CYTOPLASM – Located outside the nucleus and inside the plasma membrane
Found in both plants & animals
Found in prokaryotic & eukaryotic cells
Consists of 3 major elements
Cytosol
Organelles
inclusions

20. CYTOPLASM – 3 major elements of cytoplasm
Cytosol – semitransparent fluid which suspends the organelles
Organelles – “little organs” of cell where all cell functioning occurs
Inclusions – non-functioning units of the cell such as lipid droplets,, melanin (color pigment), etc.

21. MITOCHONDRIA – (aka) POWERHOUSE OF CELL
In the cell’s cytoplasm
Found in both plants & animals
Found only in eukaryotic cells only
Consists of a double layer membrane surrounding “sausage-like” structures which can move and wriggle about
Functions to carry out the reactions which use O2 to break down food into cellular energy (ATP)
Found most in metabolically busy cells such as the liver & muscle cells

22. RIBOSOME – cell’s protein factories
In the cell’s cytoplasm – tiny dark bilobed bodies of protein
Ribosomal RNA – (rRNA)
Some float free but most are attached to the Rough Endoplasmic Reticulum
Found in both plants & animals
Found in eukaryotic cells as well as prokaryotic cells
Not membrane bound in prokaryotic cells
Functions synthesize proteins for cell

23. ENDOPLASMIC RETICULUM – (aka) ER
In the cell’s cytoplasm
Found in both plants & animals
Found only in eukaryotic cells ONLY
A “network” of tubules or “cisterns”
Accounts for about ½ of cell’s membranes
Functions to carry substances (primarily proteins) from 1 part of cell to another part of cell
2 forms –
Rough ER & Smooth ER

24. ROUGH ENDOPLASMIC RETICULUM – (aka) ROUGH ER
Studded with ribosomes
Site of protein synthesis
Abundant in cells that export protein products
Pancreas – insulin & other digestive fluids

25. SMOOTHENDOPLASMIC RETICULUM – (aka) SMOOTH ER
Plays no actual role in protein synthesis –
Communicates with the Rough ER & functions in lipid metabolism
Detoxifies drugs & pesticides
Abundant in:
Liver
Testes – to produce testosterone

26. GOLGI APPARATUS – (aka) GOLGI BODY
Located in the cytoplasm of cell
Found in both plant & animal cells
Found in Eukaryotic cells only
Functions to modify, package and transport proteins
2 types –
Transport Vesicles – modifies & packages proteins
Secretory Vesicles – transports proteins from Golgi Apparatus to plasma membrane

27. LYSOSOME – (aka) cell’s demolition sites
Located in the cytoplasm of cell
Found in both plant & animal cells
Found in Eukaryotic cells only
Functions to breakdown other materials
Contain powerful “digestive” enzymes
“digest worn-out or non-usable” cells or cell parts
Exocytosis – transporting materials out of cell
Abundant in white blood cells
“digest” bacteria & other foreign substances

28. PEROXISOME – Located in the cytoplasm of cell
Found in both plant & animal cells
Found in Eukaryotic cells only
Contains powerful oxidase enzymes that use molecular O2 to detoxify harmful substances
Functions to disarm free radicals – highly reactive chemicals
Look like small lysosomes
Abundant in the liver & kidneys

29. CYTOSKELETON – Located in the cytoplasm of cell
Found in both plant & animal cells
Functions to provide form & structure to cells
Found in Eukaryotic cells only

30. CYTOSKELETON – Consists of 3 types of protein filaments
Intermediate filaments – help form desmosomes to provide internal guy wires to resist pulling forces
Microfilaments – such as actin & myosin – involved in cell motility and changes in cell shape (muscle cells)
Microtubules – determine the overall shape of the cell and the distribution of organelles
Important during cell division

31. CENTRIOLES – Located in the cytoplasm of cell
Found in both plant & animal cells
Found in Eukaryotic cells only
Rod-shaped bodies that lie at right angles to each other
Made up of fine microtubules and form the mitotic spindle during cell division
Some have cilia and/or flagella

33. Cilia & Flagella –
Cilia - Microtubules used to move materials around outside of cell
Usually many of these small projections surrounding the cell or at least the exterior surface of a cell
Flagella – responsible for motility of the cell as a whole
Usually only one or a few and are long whip-like structures

34. Central Vacuole– Eukaryote / Plants
Function to give plant cells rigidity
Aka – turgidity
Can increase & decrease in size

35. Chloroplast – Eukaryote / Plants Site for photosynthesis
Light & Dark Reaction
Hold chlorophyll
Inner Membranes Enclose:
Thylakoid / Granum
Stroma Lamellae
Intermembrane Space