Cell Structures & Organelles

1. Cell Structures & Organelles Chapter 7 Section 3

2. Cytoplasm • Occurs inside the plasma membrane • Fluid portion of the cell

3. Cytoskeleton • Is a supporting network of long, thin protein fibers that form a framework for the cell and provide an anchor for the organelles inside the cell

4. Nucleus • Isolated region where the DNA is • Double membrane allowing for DNA to carry out its functions and not be affected by processes occurring in other parts of the cell

5. Without a nucleus, a cell cannot reproduce. Loss of reproductive ability is often paired w/increased specialization • Human red blood cells do not have a nuclei; they are specialized to transport oxygen

6. Ribosomes • Structures found free in the cytoplasm or attached to the ER • Always composed of a type of RNA and protein • Carry out protein synthesis

7. Endoplasmic Reticulum • Extensive network of tubules or channels that extends almost everywhere in the cell • Transportation of material throughout the internal region of the cell • Two kinds of ER: Smooth & Rough

8. Smooth ER • Has unique enzymes embedded • Production of membrane phospholipids and cellular lipids • Production of sex hormones (testosterone & estrogen)

9. Rough ER • Has ribosomes on the exterior of the channels • Protein synthesis– protein development and transport • Proteins might become parts of membranes, enzymes, or even messenger cells

11. Golgi Apparatus • Appears to be flattened sacs called cisternae, which are stacked on top of one another • Function in the collection, packaging, modification, and distribution of materials synthesized in the cell

12. Vacuoles • Occupy a very large space in the cell • Provide storage (food, wastes, water) • Vacuoles enable cells to have higher surface area to volume rations • Uptake of water in plants that provide rigidity for the organism

14. Lysosomes • Intracellular digestive centers that arise from the Golgi apparatus • Sacs bounded by a single membrane that contain as many as 40 different enzymes • Enzymes also digest bacteria and viruses that have entered the cell

15. Lysosomes also bond with older or damaged organelles from with and help recycle them

16. Centrioles • Are organelles made of microtubules that function during cell division • Located in the cytoplasm of animal cells near the nucleus

17. Mitochondria • Rod-shaped organelles that appear throughout the cytoplasm • Involve the production or usable cellular energy called ATP “cell powerhouse”

18. Chloroplasts • occur only in algae and plant cells • Capture light energy and convert it to chemical energy through a process called photosynthesis

19. Also contains grana, thylakoids, and stroma • Thylakoids are flattened membrane sacs w/ components necessary for the absorption of light

20. Cell Wall • Only found in plant cells • The cell wall is a thick, rigid, mesh of fibers that surrounds the outside of the cell membrane • Provides protection and support

21. Cilia and flagella • Cilia are short, numerous projections that look like hair • Flagella are longer and less numerous • Both are used for locomotion (movement)

22. Plant vs. Animal Plant Cells Animal Cells Nucleus present Cell wall missing Chloroplasts missing • Nucleus present • Cell wall present • chloroplasts