Chp3 cellular level Flashcards
What is the study of cells?
- cytology
* part of a broader discipline of cell biology (bio, chem and phys)
What is Cell Theory
•developed by Robert Hooke
- Cells are the building blocks of all plants and animals
- Form from preexisting cells
- smallest units that perform all vital physiological functions
- maintains homeostasis at a cellular level
How many types of cells does the human body contain and which are they?
•2
- Sex cells
- Somatic cells
What are sex cells?
- germ or reproductive cells
- the sperm in males
- oocytes in females
What are somatic cells?
- soma=body
* all the other cells in the human body
What is the plasma membrane?
- outer boundary of cell
* also called cell membrane
What does plasma membrane do?
- separates cell from surrounding environment
* performs various functions
What are the four main functions of Plasma Membrane?
- Physical isolation
- Regulation of exchange w/ the environment
- sensitivity to the environment
- Structural support
What does physical isolation do?
• barrier between cell interior and surrounding extracellular fluid (interstitial fluid)
What happens in Regulation of exchange with the environment?
- ions and nutrients enter
* waste and cellular products are released
What does sensitivity to the environment do?
- Facilitates communications
- receives information about the cells surroundings
- 1st part of cells affected by change in composition
What does structural support do?
• anchors cells and tissues
What does the Plasma membrane contain?
- Phospholipids
- Steroids
- Proteins
- Carbohydrates
What are membrane proteins?
- proteins that are much denser than lipids
* 55% of the plasma membrane
What are the two structural classes of membrane proteins?
- Integral proteins
2. Peripheral proteins
What are integral proteins?
- Part of membrane structure that can’t be removed w/o damage
- Also called Transmembrane proteins
What are Peripheral proteins?
- bound to the inner or outer surface of membrane
* easily separated from membrane
What are the functions of Membrane proteins?
- Anchoring proteins
- Recognition proteins (identifiers)
- Enzymes
- receptor proteins
- Carrier proteins
- Channels
What does anchoring proteins do?
- attach plasma membrane to other structures
- stabilize its position.
- bound to cytoskeleton
What is network of supporting filaments?
• Cytoskeleton
What does identifiers do?
- recognition proteins
* recognize other cells are normal or abnormal
What does enzymes do?
• Catalyze reaction in the extracellular fluid or cytosol
What does receptor proteins do?
• Bind and respond to Ligands
Ions, hormones
What does carrier proteins do?
• Transport specific substances across membrane
What does Channels in peripheral proteins do?
• Create pores for water and solute transport
What are membrane carbohydrates?
- Make 3% of plasma membrane weight
* components of complex molecules PROTEOGLYCANS, GLYCOPROTEINS and GLYCOLIPIDS
What are the portions of carbohydrate that extend outside the membrane called?
- Glycolaxys
* sticky sugar coat
What are the functions of Glycolaxys?
- Lubrication and protection
- Anchoring and locomotion
- Specificity and biding (receptor)
- Recognition (immune response)
What is cytoplasm?
- all materials inside the cell and outside the nucleus
* contains more protein than the extracellular fluid
What does the cytoplasm contain?
- Cytosol
2. Organelles
What is cytosol?
• intracellular fluid
What are organelles?
• Internal structures that performs most of the task to keep the cell alive.
What are the two categories of cellular organelles?
- Nonmembranous organelles
2. Membranous organelles
What does the Nonmembranous organelle include?
- Does not have a membrane
- includes the Cytoskeleton,
- microvilli,
- Centrioles,
- Cilia,
- Ribosomes and
- Proteasomes
What does the membranous organelles include?
- has a membrane
- include Endoplasmic Reticulum
- Golgi apparatus
- Lysosomes
- Peroxisomes
- Mitochondria
What is the cytoskeleton?
- Cell’s skeleton
* Provides an Internal protein that gives cytoplasm strength and flexibility (shape)
What is cytoskeleton composed of?
- Microfilaments
- Intermediate filaments
- Microtubules
What are microfilaments?
- smallest filaments
- build from protein ACTIN
- generally peripherally located
What do microfilaments do?
- Anchor cytoskeleton to integral proteins of plasma membrane
- Determine the consistency of cytoplasm
- Actin interacts with the protein MYOSIN to produce movement
What does intermediate filaments do?
- Mi size
- stabilizes the position of organelles
- anchor to surrounding cells
What are microtubules?
- large hollow tubes
- Built from protein Tubulin
- Largest component of cytoskeleton
What does microtubules do?
- Gives cell its strength
- Its a vesicle transport
- form spindle during Cell division
What are thick filaments?
- Massive bundles of subunits
- composed of person MYOSIN
- Appear only in muscle cells
What is Microvilli?
• Small finger shaped projections
What does Microvilli do?
• Increase the surface are of the cell for absorption
What are centrioles?
- Cylindrical structures
* Built from 9 microtubule triplets
What does centrioles do?
• form spindle apparatus during cell division
What is the centrosome?
- Cytoplasm surrounding the centrioles
* the heart of the cytoskeletal system
What is cilia?
- cilium for singular
- Long, thin extensions from the cell
- 9 PAIRS of microtubules
What does Cilia do?
• move fluids across the cell surface
What builds polypeptides?
- Ribosomes
* Responsible for protein synthesis
What are the two major types of functional ribosomes?
- Free ribosomes
2. Fixed ribosomes
What do free ribosomes do?
- scattered through the cytoplasm
* manufacture proteins for cell
What do Fixed ribosomes do?
- attached to Endoplasmic Reticulum
* Manufacture proteins for secretion
What are Proteasomes?
• Organelles that contain an assortment of protein digesting enzymes
What is phospholipid bilayer?
- Phospholipid molecules in the Plasma membrane that form two layers
- forms most of surface are
- 42% of its weight
- hydrophilic
- hydrophobic
What is the Endoplasmic Reticulum (ER)?
- network of intracellular membranes
* connected to the nuclear envelope
How many and what are the major functions of ER?
• 4
- Synthesis
- Storage
- Transport
- Detoxification
What does ER synthesize?
- proteins,
- carbohydrates and
- lipids
What does the ER store?
•synthesized molecules and materials
What does ER transport?
• materials w/in the ER
What does ER detoxifies?
• Drugs or toxins
What is cisternae?
• Long hollow tubes
• Flattened sheets
• chambers
Formed by ER
What is Smooth Endoplasmic Reticulum?
- Does not have ribosomes attached to it
* synthesizes lipids and carbohydrates
What lipids and carbohydrates does SER synthesize?
- phospholipids and cholesterol (membranes)
- steroids (reproductive system)
- Glycerides ( liver and fat cells)
- Glycogen ( muscles)
What is Rough Endoplasmic reticulum?
- system covered with Ribosomes
* combination of workshop and shipping warehouse
What does the RER do?
- Active is protein and glycoprotein synthesis
- Facilitates Polypeptide folding into correct protein structures
- encloses products in TRANSPORT VESICLES
What are the 3 main functions of Golgi Apparatus?
• modifies and aorta protein
1. Modifies and packages secretion
•hormones or enzymes thought exocytosis
- Renews or modifies the Plasma membrane
- Packages special enzymes w/in vesicle for use in the cytoplasm
What are Lysosomes?
- powerful digestive enzymes-containing vesicles
* eats them
What do lysosomes do?
- degrade old organelles
- degrade extracellular materials
- degrade damaged cells