Test 2-diffusion, Endomembrane System Flashcards
Why is a larger SA to V ratio more efficient, are smaller or bigger cells better
Smaller ratio requires more nutrients and creates more waste, but takes longer for the waste to leave and nutrient to get in, smaller cells are better because they have a larger ratio
What is the cytoplasm composed of
Composed of water, salts, and dissolved organic molecules
Whatre integral and peripheral proteins
Integral goes through both layers of bilayer, peripheral are only found on the top or bottom of the bilayer
What do carbohydrates do
Carbohydrate chains attach to form glycolipids and glycoproteins
What do glycoproteins do
Functions in cell recognition, cell signaling
What do glycolipids do
Maintain stability of cell membrane
What do channel proteins do
Give a path for molecules that cannot enter alone in the plasma membrane
What do carrier proteins do
Help carry molecules past the bilayer
What do receptor proteins do
Recieve molecules, such as hormones
What do enzymatic proteins do
Proteins that are also enzymes, catalyzing chemical reactions
What does cholesterol do, where is it found
Found embedded in the bilayer (integral), helps stabilize and give shape
What can pass the plasma membrane easily
Small, uncharged molecules (O2, CO2)
What cannot pass the membrane easily
Large proteins and tiny, polar, or charged molecules
What is simple diffusion
Passive transport that doesnt require the help from proteins
What is facilitated diffusion
Passive transport that requires protein carriers/channels specific to the transported substance
Do all carriers and channels require ATP
Some do, some dont
What is passive transport and diffusion
Another name for diffusion, particles going from high to low concentration
What is osmosis
Diffusion of water from high to low concentrations
How does the sodium potassium pump work, where is it active
Active in all animal cells
A carrier protein that moves sodium ions to the outside of the cell and potassium ions to the inside
What is a pump
A carrier protein required in active transport
What does it mean for the sodium potassium pump to exist in two conformations
It opens on both sides
When is exocytosis or endocytosis used
Generally for transporting much larger molecules/ many molecules at once
What is exocytosis, give an example
Vesicles fuse with plasma membrane for secretion
Ex. Pancreas calls release digestive enzymes
Insulin is secreted due to rising blood glucose levels
What is endocytosis, what are the three types and examples of them
Cells take in substance by forming a vesicle around it
1. Phagocytosis: taking in large particles, like white blood cells consuming antigens
2. Pinocytosis: taking in small particles (but can do so in bulk), used in kidneys and intestines
Receptor mediated endocytosis: involves specific particles like hormones and nutrients through receptor binding
Used in placentas
What is the pressure that helps with homeostasis of water, how is it formed
Osmotic pressure is the pressure that builds up in a system due to osmosis
If enough, can prevent excess amounts of water to enter, maintaining homeostasis
What happens to a plant or animal cell in a hypotonic solution?
Plant: swells and expands
Animal cells swell and possibly burst (lyse)
Why do plant cells not burst in hypotonic solutions?
The cell wall is rigid and resists the expansion of the cell membrane pushing against the wall by increaed turgor pressure
What happens to plant and animal cells in hypertonic solutions
Plant: undergo plasmolysis
Animal cells: crenation
What is plasmolysis
Cytoplasm shrinks, membrane separates from the cell wall
What is the endomembrane system
A group of interconnected organelles in eukaroytic cells that work together to modify, package, and transport lipids and proteins
Whatre carrier proteins and how are they different from channel proteins
Proteins that bind to a specific molecule and undergo a conformational change, releasing the molecule on the other side of the membrane afterwards
Very specific to the transported molecule (more specific than channels)
What does the nuclear envelope do, where is it
Surrounds the nucleus and is connected to RER
Has pores that regulate exchange of genetic materials between the nucleus and the cytoplasm
Allows mrna to travel to RER
What does the RER do and make, where do they send the created molecule to
Synthesizes proteins, sends them to golgi body through transport vesicles
What does the SER do, where does it send the created molecule to
It makes lipids and detoxifies substances
Sends to golgi body through transport vesicles
What does the golgi body do, what does it make
Makes transport vesicles and secretory vesicles
Receives proteins and lipids, modifying and packaging them into vesicles
How are materials sent to lysosomes
Sent from the golgi body or by endocytosis
Whatre the three types of vesicles and where are they made
Transport vesicles used around the cell, made by golgi body and ER
Secretory vesicles used outside the cell, made by golgi body
incoming vesicles used inside the cell, made by cell membrane
