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
Proteasomes
Contain enzymes, their Job is to degrade other protein (to recycle and redirect , turn on and off, pathways)
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.
peroxisomes
- Neutralizes toxic compounds created by own cells.
- Are different from lysosomes, more for purifying and filtering. (peroxide, purify)
mitochondria
Produce energy (ATP)
3 pathways
1. Glycolysis (chop chop chop chop)
2. Krebs cycle
3. Chop chop chop -> enters electron transport chain
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)
lysosomes
What is autolysis?
- Gets rid of damaged cells, or destroys bacteria (important for immunity). Much more powerful at destroying
- autolysis is a type of self-suicide by the cell