Molecules make Cells possible: Sugars for energy Proteins for building structures Lipids for cell membranes DNA/RNA for making more cells ATP for making energy possible
Prokaryotes vs. Eukaryotes DNA in single loop Very small No organelles Live in all environments DNA in chromosomes in nucleus Much larger Organelles handle complex cell tasks Live in restricted environments
Prokaryotic cells are structurally simpler than eukaryotic cells Prokaryotic cell Nucleoid region Nucleus Eukar yotic cell Organelles Colorized TEM 15,000 Figure 4.3A
Surface Area to Volume Ratio A small cell has a greater ratio of sur face area to volume than a large cell of the same shape 30 m 10 m 30 m 10 m Surface area of one large cube 5,400 m 2 Total surface area of 27 small cubes 16,200 m 2 Figure 4.2B
Eukaryotic cellsplants, fungi, animals, protists Nucleus present Membrane surrounds cell Cell wall may be present (plants, fungi, but NOT animals)
Plasma membrane Surrounds entire cell Made of two lipid layers Allows certain molecules in/out = selectively permeable
Internal membrane system 3 important membranes : 1.Rough endoplasmic reticulum 2.Smooth endoplasmic reticulum 3.Golgi complex
Smooth endoplasmic reticulum has a variety of functions: 1.Synthesizes lipids 2.Processes toxins and drugs in liver cells 3.Stores and releases calcium ions in muscle cells
Rough endoplasmic reticulum makes membrane and proteins Ribosomes on the sur face of the rough ER produce proteins that are secreted, inserted into membranes, or transported in vesicles to other organelles
Lysosomes are sacs of enzymes that function in digestion within a cell Lysosomes in white blood cells destroy bacteria that have been ingested Lysosomes also recycle damaged organelles
The various organelles of the endomembrane system are interconnected structurally and functionally
Moving the cells around 3 ways: 1.Flagellumcell extends cytoplasm into tail-like structure 2.Ciliacell extends small hair-like structures 3.Pseudopodiacell extends itself to move around
Human cells move too! 1.Lung cells & fallopian tube cells use cilia to move things around. 2.Male sperm cells use a flagellum to get to the egg. 3.White blood cells use pseudopodia to move between other cells and get to where they need to be.
Organelles Membrane surrounds them Important organelles: Nucleus Cell membrane Lysosomes/peroxisomes Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi apparatus Special organelles involved in energy: Mitochondrionproduces ATP (in all eukaryotes) In plants and some algae: Chloroplastproduces sugar from light energy
Can human diseases result from organelles? Yes! Lysosomes Mitochondria Peroxisomes (in plants) Even Cell Membranes! Aging? Chronic Fatigue Syndrome?
Quick Review! What are 5 organelles in the cell? In order, what organelles are responsible for moving the products of DNA to the Golgi Complex? What 3 things make up the cell membrane? What are the 4 foundational theories of biology? What are the 4 groups of biologically- important molecules?