PDQ’s Eukaryotic Cells

4.3-4.5

1. Nuclear Envelope/Pores

• Double Phospholipid membrane around nucleus

• Contains pores to allow RNA and protein out of the nucleus.

• Function is to separate transcription from translation

2. Nucleolus vs. rRNA vs. ribosomes

• Nucleolus - makes ribosomes, inside nucleus• rRNA – ribosomal RNA, made inside nucleolus• Ribosomes – consists of 2 units; – protein synthesis, – can be found free in cytoplasm or attached to the

RER;– do not have a membrane around them; are not

considered to be organelles;

3. Free ribosomes vs. RER ribosomes

• If the ribosome made protein that is destined to be modified, then those ribosomes go and attach to the RER.

4. Endomembrane System

• RER- chemically modifies proteins and tags them for delivery and sends them out in vesicles

• SER – lipid & steroid synthesis; chemical breakdown of drugs; break down glycogen in animal cells

• Golgi Apparatus – packages and sorts proteins; adds carbohydrates to some proteins; makes polysaccharides in plant cells

• Lysosomes – originate from Golgi Body; contain digestive enzymes to break down macromolecules

5. Endomembrane System Function

• The endomembrane system is a series of compartments that work together to package, label, and ship proteins and molecules

6. Path of protein

• Part 1– RER, vesicle, CIS region of Golgi Body, Vesicle – out

from Trans Region of Golgi, plasma membrane• Part 2– Primary lysosome comes from Golgi, phagosome

comes from membrane with food, join together to form the secondary lysosome, digestion of small molecules into cytoplasm, undigested molecules gets released out of plasma membrane

7. Lysosomal storage disorder

• Lysosomes fail to digest stuff• They can be detected in cells where an

accumulation occurs due to the lack of it breaking down

8. Chloroplasts and mitochondria

• No, they are not a part of the endomembrane system, though they contain membranes around them.

9. Functions of chloroplasts and mitochondria

Chloroplasts• photosynthesis

Mitochondria• Breakdown of glucose into

ATP

10. Plastids

• Big category of many organelles which store pigments, carbohydrates, lipids or protein

• Chloroplast is an example

11. Chloroplasts, Chromoplasts, Leucoplasts

• Chloroplasts – contains chlorophyll (green)• Chromoplasts – yellow and red pigments• Leucoplasts - colorless

12. Peroxisomes and Vacuoles

• They are not a part of the endomembrane system

13. Peroxisomes

• Small organelles that accumulate toxins such as H2O2.

• Break down this H2O2 into water and oxygen

14. Vacuole Functions

• Storage of food, water, waste, pigments and enzymes

• Structure – take up 90% of cell volume• Reproduction – storing pigments attracts

animals which assists in pollination• Catabolism – enzymes break down proteins

etc.

15. Plants waste

• Central Vacuole contains digestive enzymes to help break down things

16. Mitochondria and chloroplast

16 continued… endosymbiotic theory

• Chloroplast and mitochondria both have their own DNA

17. Cytoskeleton

• Supports cell• Maintains cell shape• Controls organelles and their movement• Involved with cytoplasmic streaming• Interacts with extracellular structures• Helps to anchor cell in place

18. Microfilaments

• Bundles 7 nm in diameter

• Made up of the protein actin

• Help cell to move• Determine and

stabilize cell shape

18. Intermediate filaments

• Tough ropelike protein assemblages, 8-12 nm

• Anchor cell structures in place

• Resist tension

18. Microtubules

• Largest diameter, long and hollow

• Form a rigid skeleton• Act as framework along

which motor proteins can move structures in cell

19. Cilia and Flagella

• Made of a 9+2 pattern of microtubules

• These microtubules slide past each other driven by a motor protein called dynein powered by ATP

20. Centriole

• Same as cilia