ch. 03 cell
DESCRIPTION
Also includes DNA, RNA and mitosisTRANSCRIPT
![Page 1: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/1.jpg)
Chapters 3 & 4
Cells, DNA, Mitosis & RNA
![Page 2: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/2.jpg)
Cells
• vary in size• vary in shape• measured in micrometers
![Page 3: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/3.jpg)
A Composite Cell
• hypothetical cell• major parts
• nucleus• cytoplasm• cell membrane
![Page 4: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/4.jpg)
Cell Membrane
• outer limit of cell
• selectively permeable – controls what moves in and out of the cell
•phospholipid bilayer • hydrophilic water-soluble “heads” form surfaces• hydrophobic water-insoluble “tails” form interior
![Page 5: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/5.jpg)
Cytoplasmic OrganellesEndoplasmic Reticulum
• transportation system• Rough ER
• studded with ribosomes• protein and lipid synthesis
• Smooth ER• lipid synthesis• break down of drugs
Ribosomes• free floating or connected to ER• site of protein synthesis
![Page 6: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/6.jpg)
Cytoplasmic Organelles
Golgi apparatus• group of flattened, membranous sacs (pancakes)• packages and modifies proteins then ships• “Fed Ex”
Mitochondria• powerhouse of the cell (energy) ATP• looks like a jellybean with squiggles
![Page 7: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/7.jpg)
Cytoplasmic Organelles
Lysosomes• digest worn out cell parts or unwanted substances via enzymes•Like “Lysol” they kill unwanted things
Peroxisomes• break down organic molecules
Centrosome• two rod-like centrioles• distributes chromosomes during cell division
![Page 8: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/8.jpg)
Cytoplasmic Organelles
Cilia• short hair-like projections• propel substances on cell surface
Flagellum• long tail-like whip• provides motility to sperm
![Page 9: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/9.jpg)
Vesicles• membranous sacs• store substances •GA and ER packs things into vesicles!
Microfilaments and microtubules• thin rods and tubules• give cytoplasm strength• allows for movement of organelles
Cytoplasmic Organelles
![Page 10: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/10.jpg)
Cell Nucleus
• control center of cell
• nuclear envelope• porous double membrane• separates nucleoplasm from cytoplasm
• nucleolus• dense collection of RNA and proteins• site of ribosome production
• chromatin• fibers of DNA and proteins• stores information for synthesis of proteins
![Page 11: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/11.jpg)
Structure of DNA
Pages 115-117•Double helix•Sugar and phosphates on the sides•Bases pairs as the rungs
• Adenine and Thymine (2)•Cytosine and Guanine (3)
• DNA wrapped about histones forms chromosomes
![Page 12: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/12.jpg)
DNA Replication
1. Unwind2. Unzip3. Complementary base
pairs (AT, CG)A. In orderB. Okazaki
fragments4. Proofreading enzyme5. Winds back up again
![Page 13: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/13.jpg)
Simple Diffusion
• movement of substances from regions of higher concentration to regions of lower concentration• requires no energy, happens naturally
![Page 14: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/14.jpg)
Facilitated Diffusion
• diffusion across a membrane with the help of a channel or carrier molecule•Still requires no energy
![Page 15: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/15.jpg)
Osmosis• movement of water through a selectively permeable membrane from regions of higher concentration to regions of lower concentration• Diffusion of water• Still no energy needed
![Page 16: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/16.jpg)
How osmosis affects the body, especially RBCs
• Isotonic solution- same inside and out, no net change
• Hypertonic solution- solution outside is stronger so water leaves the cell to dilute the outside; cell shrivels
• Hypotonic solution- solution outside is weaker so water goes into the cell to dilute the cell; cell swells and may burst
![Page 17: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/17.jpg)
Filtration
• smaller molecules are forced through porous membranes• Ex: molecules leaving blood capillaries• Still requires no energy
![Page 18: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/18.jpg)
Movements Into and Out of the Cell
Passive Transport• NO cellular energy• simple diffusion• facilitated diffusion• osmosis• filtration
![Page 19: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/19.jpg)
Active Transport• carrier molecules transport substances across a membrane from regions of lower concentration to regions of higher concentration• “going against the flow”• REQUIRES ENERGY
![Page 20: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/20.jpg)
Endocytosis• cell engulfs a substance by forming a vesicle around the substance•REQUIRES ENERGY
Pinocytosis- cell drinking Phagocytosis- cell eating
![Page 21: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/21.jpg)
Exocytosis• reverse of endocytosis• substances in a vesicle fuse with cell membrane• contents released outside the cell• REQUIRES ENERGY
![Page 22: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/22.jpg)
Transcytosis
• endocytosis followed by exocytosis• transports a substance rapidly through a cell• Ex: HIV crossing a cell layer
![Page 23: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/23.jpg)
Movements Into and Out of the Cell
Passive (Physical) Processes• NO cellular energy• simple diffusion• facilitated diffusion• osmosis• filtration
Active (Physiological) Processes• REQUIRE cellular energy• active transport• endocytosis• exocytosis• transcytosis
![Page 24: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/24.jpg)
The Cell Cycle
• 4 major stages • interphase• mitosis• cytokinesis•differentiation
![Page 25: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/25.jpg)
Interphase
• very active period• cell grows• cell maintains routine functions
•Divided into 3 phases• G1 phase – cell grows and synthesizes organelles• S phase – DNA replication• G2 phase - more cell growth until mitosis occurs
![Page 26: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/26.jpg)
Mitosis
• produces two daughter cells from an original cell• Stages (PMAT)
• Prophase – chromosomes become visible; nuclear envelope disappears; centrioles move to opposite sides
• Metaphase – chromosomes line up down the middle
• Anaphase – chromosomes move apart to opposite sides
• Telophase – chromosomes uncoil; nuclear envelope forms (opposite of prophase)
![Page 27: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/27.jpg)
Mitosis
![Page 28: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/28.jpg)
Cytokinesis
• begins during anaphase• continues through telophase• contractile ring pinches cytoplasm in half
![Page 29: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/29.jpg)
Differentiation
![Page 30: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/30.jpg)
Tumors
Two types of tumors• benign – usually remains localized• malignant – invasive and can metastasize; cancerous
Genes that cause cancer• oncogenes – activate other genes that increase cell division• tumor suppressor gene – normally regulate mitosis; if inactivated they will not regulate mitosis
![Page 31: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/31.jpg)
RNA Molecules
Messenger RNA (mRNA) -• delivers genetic information from nucleus to the cytoplasm
• single polynucleotide chain
• formed beside a strand of DNA
• RNA nucleotides are complementary to DNA nucleotides (exception – no thymine in RNA; replaced with uracil)
• making of mRNA is transcription
![Page 32: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/32.jpg)
RNA Molecules
Transfer RNA (tRNA) -• carries amino acids to mRNA• carries anticodon to mRNA• translates a codon of mRNA into an amino acid
Ribosomal RNA (rRNA) –• provides structure and enzyme activity for ribosomes
![Page 33: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/33.jpg)
Protein Synthesis
![Page 34: Ch. 03 Cell](https://reader036.vdocuments.site/reader036/viewer/2022062300/556ba58cd8b42a207e8b49f9/html5/thumbnails/34.jpg)
Protein Synthesis