Chapter 3: The Cellular Level of Organization Flashcards
What is Cell theory?
- Made of the cells, smallest living unit
- Maintain homeostasis
- Smallest units that perform all vital physiological functions
What is cytology?
the study of cells
What are the 2 main types of cells?
- Sex cells - sperm and oocytes
- Somatic cells - all body cells except sex cells
What are the 3 main components of a Cell? which organelles are which category?
- Plasma membrane
- Nonmembranous organelles
- Membranous organelles
When looking at the shape of a cell, what are some special looking cell structures? Where are these specific cells found? What determines the cell structure?
- Flagellum - long whip-like tail. Found in sperm.
- Cilia - long hair-like structure on the membrane, job is to move mucous and fluids across cell surface. Found in the respiratory and reproductive tracts.
- Microvilli - short hair-like structures. Increases the surface space for better absorption. Mainly in small intestine. Attach to cytoskeleton.
*some cells have flagellum, some have cilia, some have neither.
*Cytoskeleton determines cell structure
What is the job of the Plasma Membrane?
- Barrier wall, anchors cells to others
Cells to cells Or cells to matrix / lamina - Semipermeable (selective in substances that passes through membrane)
What is the Plasma Membrane made of?
Phospholipid bilayer - head of lipid are hydrophilic, legs are hydrophobic.
- Integral proteins (they’re “integrated”) in the cell membrane
- Integral proteins - (“integrated” through the whole membrane. Like a channel for ions, opens and closes for very specific things.
- channel proteins: no energy needed, goes with the flow.
- carrier protein: like a protective baseball glove for certain substances. sometimes use energy to go against higher concentration.
- Peripheral Proteins in the cell membrane (in the “periphery”)
- peripheral proteins - (on the “peripheral” or outside of the membrane. Bound to inner or outer surface of membrane.
- anchoring proteins: stabilizer, attach to outside structures
- receptor proteins: bind and respond to ligands (ions, hormones)
- CD proteins (“recognition” - don’t use…)
*enzymes catalyze reactions
What are the 2 categories of transportation across the cell membrane?
- Active Transportation - goes from low concentration to high concentration forcefully. Requires energy.
- Passive Transportation - moves from high concentration to low concentration. 2 kinds of passive…
-1. Simple Diffusion - does NOT require a transport protein. goes from high concentration to low concentration easily.- Facilitated Diffusion - requires the help of a Transport Protein. still moves from high concentration to low concentration.
Membrane Carbohydrates
Membrane Carbohydrates
- The sugars: Proteoglycans, glycoproteins, and glycolipids. Form a sticky substance on the outside of the cell.
What are the 2 components of Cytoplasm?
- Cytosol (intracellular fluid)
- Organelles (structures)
Organelles come in 2 types - with or without membranes.
- non-membranous organelles (direct contact with cytosol)
- cytoskeleton, centrioles, ribosomes, proteasomes, microvilli, cilia, and flagella
- membranous organelles (have a plasma membrane)
- ER, golgi, lysosomes, peroxisomes, mitochondria, nucleus
What are Inclusions in the cell?
- masses of anything that is insoluble
Cytoskeleton (the Zipline.) What is it made of? What is it’s function?
- microfilaments: made of proteins. provide the structure inside the microvilli, like the inside of a saguaro cactus.
- microtubules: change cell shape
*I don’t know the difference.
Centrioles (like twizzler twins)
- always a pair. When cells are dividing in mitosis, they become 2 pairs and they hook and pull apart the chromatin.
- centrioles are surrounded by a cytoplasm called the “centrosome”
Ribosomes. 2 kinds..
- Synthesize proteins
- free ribosomes (freely floating)
- fixed ribosomes (on RER)
Contain ribosomal DNA (rRNA)
*a single ribosome looks like a drawing of hamburger buns
Endoplasmic Reticulum (2 kinds)
- Smooth Endoplasmic Reticulum (SER) - synthesizes lipids and carbohydrates
- for membranes
- for glycerides (storage in liver and fat cells)
- for glycogen (storage in muscles and liver cells)
- for steroid hormones and cholesterol
- Rough ER (RER) - synthesizes proteins by folding and changing their shape into usable protein structures.
*chambers are “cisternae” with entry and exit points
*neatly packages products into vesicles –> golgi
Golgi
- Receive vesicles (protein, lipids, carbohydrates)
- Vesicles fuse with the golgi
- Also has entry and exit
- Will be modified again (adding / subtracting)
- In the exit, the secretory vesicles
*some become lysosomes, others renew the cell membrane.
Nucleus:
Outer to Inner:
- Nuclear membrane (with nuclear pores)
- Nucleoplasm (with chromatin floating around)
- nucleolus - the central office of the nucleus (where ribosomes and rRNA synthesized)
pinocytosis and phagocytosis
Phagocytosis: where the cell membrane “eats” a large object, such as bacteria.
Pinocytosis: where the cell membrane “eats” small objects with lots of extracellular fluid.
Describe the process of Protein synthesis: Transcription
Where does this take place?
In the nucleus:
1. Transcription (C comes before L)
- mRNA (messenger RNA) is produced by the unzipping of DNA by the enzyme RNA polymerase. Editing of the mRNA is done and there are leftovers: “exons” are useable codons and are matched for the exit, “introns” are removed and stay “in”.
What is a triplet codon?
What is a gene?
- codon: triplet set of amino acid pairs.
- gene: section of DNA
Describe the process of Protein synthesis:
Translation: Where does this take place?
(L for Later)
Outside the nucleus:
- mRNA leaves the nucleus and binds with a free ribosome or fixed ribosome on the RER. The RER neatly folds the proteins into useable shapes, then send off to the Golgi
*ribosome = made of protein + ribosomal RNA (rRNA)
Translation:
- each mRNA codon translates to 1 amino acid. Ribosomes scan the mRNA barcode and match tRNA (transfer RNA) to matching nucleic acid side, with an amino acid at the other end. Continue scanning, and the amino acids build up to form peptides, or a chain of proteins
- Prophase
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chromatin coils to chromosomes. Now like dreadlocks. signature X shape.
- Metaphase
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Equatorial plane (like equator). Chromosomes will line up along the plane.
“M” for Middle line
- Anaphase
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Chromative X (one arm goes one leg, other arm goes other way, same with legs)
Centrioles pull chromosomes apart. “A” for Away.
- Telophase
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Each new cell structures begin to reform themselves with the new material. “T” for Two
Isotonic, hypotonic, and hypertonic Solutions
- Hemolysis and crenation
*Solutions are relative to the cells.
- solutes and water molecule ratios
*water moves to the area with HIGHER solute concentration, (which is the area with the lower water concentration)
Isotonic Solution - “same” concentration of water molecules in both inside and outside
Hypotonic Solution- Lower solute concentration in the solution outside the cell than inside = swelling of the cell with water, which could lead to a burst of the cell (hemolysis)
Hypertonic Solution - higher solute concentration in the solution outside the cell, than inside the cell = shrinking of the cell as water moves to the outside (crenation)
