This document summarizes key aspects of cell structure and function. It describes the basic components of cells, including the plasma membrane, DNA, and cytoplasm. It distinguishes between prokaryotic and eukaryotic cells, noting that eukaryotic cells are larger and contain membrane-bound organelles like the nucleus, mitochondria, and chloroplasts. The document also provides details on specific organelles and their functions, similarities and differences between plant and animal cells, and a brief overview of viruses.

1. Cell Structure and Function

2. Attributes of cells A. Plasma membrane B. DNA C. Cytoplasm D. Obtain energy and nutrients from their environment

3. 1. 1–100µm 2. Why is there a limit to cell size? a. Surface-to-volume ratio b. Distance from surface to center Cell Size

4. adult human tallest trees chicken egg frog embryo most eukaryotic cells mitochondrion most bacteria virus proteins atoms diameter of DNA double helix

6. Prokaryotic —no nucleus, circular DNA, ribosomes Eukaryotic —larger, nucleus, linear chromosomes, membranous organelles Cell types

7. Prokaryotic Cells Have no membrane-bound organelles Include true bacteria On earth 3.8 million years Found nearly everywhere Spores in each breath; intestines Naturally in soil, air, hot springs

8. ribosomes cell wall plasma membrane food granule prokaryotic flagellum cytoplasm nucleoid (DNA)

9. Eukaryotic Cells Have numerous internal structures Various types & forms Plants, animals, fungi, protists Multicellular organisms

10. flagellum cytoplasm rough endoplasmic reticulum ribosome microtubules lysosome mitochondrion Golgi complex plasma membrane intermediate filaments vesicle smooth endoplasmic reticulum free ribosome vesicle nuclear pore chromatin (DNA) nucleolus nuclear envelope nucleus

11. chloroplast central vacuole rough endoplasmic reticulum ribosomes microtubules (part of cytoskeleton) cell wall mitochondrion Golgi complex plasma membrane intermediate filaments smooth endoplasmic reticulum free ribosome vesicle nuclear pore chromatin nucleolus nuclear envelope nucleus

12. Eukaryotic cell structure Nucleus is control center of the cell 1. Membrane bound (nuclear envelope) 2. Contains nucleoli; synthesizes ribosomal RNA 3. DNA in chromosomes (DNA and proteins)

13. nuclear pores chromatin nucleolus nuclear envelope

14. nuclear pores nucleus

15. chromosome chromatin

16. 0.05 micrometers

17. Eukaryotic cell structure Organelles Endoplasmic reticulum consists of folded membranes attached to the nucleus Rough ER is site of protein synthesis and protein secretion

18. 0.5 micrometers smooth endoplasmic reticulum vesicles ribosomes rough endoplasmic reticulum 0.5 micrometers

19. Eukaryotic Cell Structure Organelles (cont.) Ribosomes assemble amino acid into polypeptide chains a. Associated with the ER b. Composed of RNA and proteins

20. 0.5 micrometers ribosomes rough endoplasmic reticulum

21. 0.5 micrometers smooth endoplasmic reticulum vesicles

22. Eukaryotic Cell Structure Organelles (cont.) Golgi apparatus are membranous sacs associated with ER a. Processing and transport of proteins, lipids b. Synthesis and transport of polysaccharides

23. Golgi complex vesicles from ER vesicles leaving Golgi complex

24. Eukaryotic cell structure Organelles (cont.) Lysosomes are Golgi-derived vesicles containing digestive enzymes

25. Golgi complex vesicles from ER vesicles leaving Golgi complex

26. Eukaryotic Cells: Organelles Energy sources for cell activities Mitochondria provide energy for cellular functions (respiration) a. Membrane bound, numerous b. Matrix/cristae c. Have their own DNA and ribosomes; self-replicate

28. 5 micrometers

29. Eukaryotic Cells: Organelles Energy sources for cell activities Chloroplasts—function in photosynthesis 1) Green—contain chlorophyll pigment 2) Stroma/grana (thylakoid stacks) 3) Have their own DNA and ribosomes; self-replicate 4) Up to 100 per cell

32. Eukaryotic Cells: Organelles Cytoskeleton Internal infrastructure Surface structures extensions of the plasma membrane aid in movement of simple organisms

33. tubulin subunit actin subunits subunit

36. Prokaryotes & Eukaryotes Similarities & differences Both surrounded by plasma membrane, but very different Prokaryotes – Archaebacteria and Eubacteria Eukaryotes – everything else

37. Evolution of Eukaryotic cell Endosymbiotic Hypothesis Similarities between bacteria, mitochondria and chloroplasts Self-reproducing by binary fission Size of organism and genome Single circular naked DNA Proportion of (G & C) to (A & T) Same sized ribosome Protein synthesis inhibited by antibiotics Enzymes for synthesis of DNA, RNA and protein Electron transport system

39. Plant & Animal Cells Similarities Both constructed from eukaryotic cells Both contain similar organelles Both surrounded by cell membrane

40. Plant & Animal Cells Differences Plants have Cell wall – provides strength & rigidity Have chloroplasts, photosynthetic Animals have Other organelle not found in plants (lysosomes formed from Golgi) Centrioles, important in cell division

41. Brief Look at Viruses Viruses are acellular Not considered to be living Cause serious diseases in most organisms