Details of Cell Structure Day 1 or 2
Eukaryotes and Prokaryotes • Eukaryotes are species with cells containing a nucleus (like onions) • Prokaryotes don’t have nuclei in their cells (many bacteria) • We will focus on eukaryotes (since that’s what humans are) to study cancer treatments
Cellular Competition • There are countless metaphors for the cell-create your own metaphor and explain to the other group(s) • Example: the cell is like a factory- the nucleus is the control center…
Themes for this unit • Structure correlates with function • Biochemical pathways are interrelated • The cell is highly developed and safeguarded- there are always multiple ways to do the same thing
Cytoplasm • Jelly-like • Gives the cell shape and flexibility • Contains all the organelles • The lightly stained region of the onion cell • Cytoskeleton provides structural suppot
Nucleus • The brain of the cell • One of the largest organelles • Surrounded by a complex double membrane- nuclear envelope • Has a section for keeping chromosomes- the wrapped up DNA • Makes ribosomes and exports them
Ribosomes • Protein making machine! • Made of proteins and RNA (similar to DNA) • 2 subunits- when they join they can produce protein • Stuck in the cytoplasm or attached to the rough endoplasmic reticulum
Cancer Connection • Imagine you are a cancer cell- your main goal is to replicate as much as possible. What should you do to your mitochondria?
Answer • Replication is extremely energy- intensive so you might answer that cancer cells make more mitochondria or prevent mitochondrial apoptosis- the death of mitochondria • We will learn a little about biochemical pathways to see that the real answer is MUCH more complex! (cancer cells actually don’t like using mitochondria)
Rough Endoplasmic Reticulum • Network of weaving membrane with ribosomes stuck on • Many sack like structures attached to the ER • Inside each sack is the lumen (sort of like another cytoplasm) • The ribosomes stuck to the ER also make protein- but these proteins are meant to be stuck in membranes or exported from the cell
Practice • How does the structure of the ER help it serve its function? • Function: Help make proteins to be stuck in the membrane or pass through the membrane
Answer • As the protein is synthesized, it is embedded directly into membrane (the ER sacks) that is hydrophobic • The lumen provides a controlled environment for protein folding
Smooth ER • Primarily a lipid processing center • No ribosomes = no proteins made • Note: again the membrane folds of the ER are useful for dealing with hydrophobic substances
Lysosomes • Solid waste processing bubbles • Filled with enzymes to degrade unwanted materials • Can destroy almost anything! • What pH do you expect inside the lysosome?
Mitochondria • Energy producer • The energy currency inside the cell is ATP (for us its something like Kilowatt hours) • Contains all the enzymes to make ATP from acetyl coa (a product of glucose and lipid processing- our food)
The task • Get into groups of 7 • Take 1 page and divide the roles among all 7 of you • Each person has a different role (nucleus, outer membrane, etc.)- described on their page of the packet