Lecture Exam 2 Flashcards
Who was Matthias Schlieden
He was a botanist
Who was Theodor Schwann?
He was a zoologist
What are the 3 main characteristics of a cell?
- They are the building blocks for all living things
- It is the unit of structure, physiology, and organization in living things
- It retains a dual existence as distinct entity and building block of organisms
What is the cell theory?
- Cells are the simplest, smallest units of life
- Cells may only arise from pre-existing cells
- All metabolic events occur within cells
What happens when you increase cell volume?
It causes issues to the cell membrane
What affects the rate of diffusion?
- Surface area
- Temperature
- Concentration gradient
- Distance
What is the role of the cell membrane?
Acts as protection
What is the role of the golgi apparatus?
It is the receiving and sending center
It receives proteins and delivers to their destinations
What are the roles of a vesicle?
It ships proteins eternally to the nucleus
Secretes proteins to the outside of the cell
What is the lysosome?
It is the stomach cells
What is sent to the lysosome?
Debris, worn out, or damaged parts
What is the mitochondria?
It is the powerhouse of the cell
What is the role of the mitochondria?
Cellular respiration
What do the centrioles aid?
Cell division
What are the roles of the cytoskeleton?
Maintains cell shape
Anchors cell with extracellular matrix
What is the apical part of the cell?
It is the top domain
What is the apical domain of the cell responsible for?
- Protection
- Absorption
- Secretion
What is the basolateral?
It is the side and bottom domain of the cell
What is the basolateral responsible for?
Anchorage and communication to neighboring cells
Define cytoplasm
It is the material between plasma membrane and the nucleus
Define plasma membrane
It encloses most the organelle
What is the role of the plasma membrane?
It organizes and protects the cell
Which head is soluble in water?
Polar/hydrophilic head
Which head is not soluble in water?
Fatty acids/nonpolar head
Define semipermeable
Some substance can flow through it freely
What is the role of cholesterol?
It is used to maintain the stability of the cell
Define cytosol
A viscous, semitransparent fluid substance of cytoplasm in which other elements are suspended
Define cytoplasmic organelles
Specialized cellular compartments or structures, each performing its own job to maintain the life of the cell
Define inclusions
Chemical substances such as glycogen granules and pigment
What is the role of hydrostatic properties?
They help cells maintain their shape
What functions are biological membranes involved in?
- Import and export
- Compartmentalization
- Cell signaling, they respond to environment
- Cell and nuclear division
- Production of energy intermediates
What are the characteristics of polar heads?
- Made by glycerol and phosphate
- The tail is made of 2 fatty acids, hydrophobic cells
- Increases the flexibility of the cell membrane
What is the percentage breakdown for lipids?
75% phospholipids
5% glycolipids
20% cholesterol
Define phosphate heads
They are polar and hydrophilic
Define fatty acid tails
They are non polar hydrophobic
Define glycolipids
Lipids with polar sugar groups on outer membrane surface
What is the role of cholesterol?
It increases membrane stability
What are the two types of membrane proteins?
- Integral proteins
2. Peripheral proteins
What are the characteristics of integral proteins?
- They are firmly inserted into the membrane
- They have hydrophobic and hydrophilic regions
What is the function of integral proteins?
They transport proteins, enzymes, or receptors
What are the characteristics of peripheral proteins?
- They are loosely attached to integral proteins
- They include filaments on intracellular/extracellular surface for membrane support
What is the function of peripheral proteins?
They are enzymes or motor proteins that are involved in mechanical functions, such as changing cell shape during cell division and muscle cell contraction
What are the 6 functions of membrane proteins?
- Transporter
- Cell-surface receptor
- Attachment to cytoskeleton and extracellular matrix
- Enzyme
- Intercellular joining
- Cell-to-cell adhesion
Define osmosis
Movement of water across a membrane
What kind of energy is osmosis an example of?
Kinetic energy
Define tonicity
How a solution affects cell volume
Define simple diffusion
Substances diffuse directly though the lipid bilayer
What substances diffuse during simple diffusion?
Gases, steroid hormones, and fatty acids
Define facilitated diffusion
The transported substance either binds to carrier proteins in the membrane and is ferried across or moves through water-filled channel proteins
Define carriers
Transmembrane proteins that are specific for transporting certain polar molecules or classes of molecules, ones that are too large to pass through membrane channels
Define vesicular transport
The transport of large particles and macromolecules across plasma membranes
Define exocytosis
Secretes substance into the extracellular space
Define endocytosis
Eats the large molecules into the cells
Define phagocytosis
Pseudopods engulf solids and bring them into the cell’s interior
Define filtration
It is a form of hydrostatic pressure, it is the formation of kidney filtrate
What is the role of cell junctions?
To aid or inhibit movement of molecules between or past cells and also see to tie cells together into tightly knit communities
What are 3 types of cell junctions
- Tight junctions
- Desmosomes
- Gap junctions
What are tight junctions?
A series of integral protein molecules in the plasma membranes of adjacent cells fuse together like the zipper of a Ziploc bag
What is the role of tight junctions?
They help prevent molecules from passing through the extracellular space between adjacent cells and restrict the movements of membrane proteins
Define desmosomes
They serve as anchoring junctions, they are mechanical couplings scattered like rivets along the sides of adjacent cells to prevent their separation
What is the role of desmosomes?
They bind neighboring cells together into sheets and also contribute to a continuous internal network of strong fibers
Define gap junctions
It is communication junction that determines what kind of stuff passes through them
Where are gap junctions found?
The heart and smooth muscle
What are the 5 types of membranous cytoplasmic organelles?
- Mitochondria
- Peroxisomes
- Lysosomes
- Endoplasmic reticulum
- Golgi apparatus
What are the 3 types of non membranous cytoplasmic organelles?
- Cytoskeleton
- Centrioles
- Ribosomes