Chap 3 : Plasma Membranes Flashcards
The cellular organelles responsible for carrying out cellular respiration, resulting in the production of ATP, the cell’s main energy carrying molecule
Mitochondria
A small, membrane-bound sac that functions in cellular storage and transport; it’s membrane is capable of fusing with plasma membrane and the membranes of the endoplasmic reticulum and Golgi apparatus
Vesicle
A cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs
Eukaryotic cell
The method of transporting material that requires energy
Active transport
A process of passing material out of a cell
Exocytosis
True or false: Enzymes are catalysts
True
Separate cells from external environment, controls passage of organic molecules, ions, water, oxygen and waste into and out of a cell
Plasma membrane
Provide structure to cell, site of many metabolic reactions, medium in which organelles are found
Cytoplasm
Location of DNA
Nucleoid
Cell organelle that houses DNA and directs synthesis of ribosomes and proteins
Nucleus
Protein synthesis
Ribosomes
ATP production/cellular respiration
Mitochondria
Oxidizes and breaks down fatty acids and amino acids and detoxifies poisons
Peroxisomes
Storage and transport, digestive function in plant cells
Vesicles and vacuoles
Unspecific role in cell division in animal cells; organizing Center of microtubules in animal cells
Centrosome
Digestion of macromolecules; recycling of worn out organelles
Lysosomes
Protection, structural support and maintenance of cell shape
Cell wall
Photosynthesis
Chloroplasts
Modifies proteins and synthesizes lipids
Endoplasmic reticulum
Modifies, sorts, tags, packages and distributes lipids and proteins
Golgi apparatus
Maintains cells shape, secures organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently
Cytoskeleton
Cellular locomotion
Flagella
Cellular locomotion, movement of particles along extracellular surface of plasma membrane, and filtration
Cilia
A scientific model that describes the structure and function of cell membranes
Fluid mosaic model
True or false: fatty acid tails are nonpolar and hydrophobic
True
True or false; phosphate heads are polar and hydrophilic
True
True or false: The plasma membrane is basically a lipid bilayer balloon filled with fluid
True
Lipid bilayer balloon filled with fluid; nonpolar tails sandwiched between polar heads; separates extracellular fluid from cytosol
Plasma membrane
Fluid mosaic model
Plasma membrane
Water loving
Hydrophilic
Water fearing
Hydrophobic
What molecules can pass through a hydrophobic core of a plasma membrane?
Small, no charge, dissolve in lipid (IE, oxygen, alcohol, steroids and carbon dioxide.
What molecules need help passing through the hydrophobic core of a plasma membrane?
Large, charged, polar (IE, water, ions, glucose
Three types of protein functions
Adhering (adheres one cell to nearby cells), tight (waterproofing/skin) and Gap (communication channels-heart)
Important membrane protein functions also include:
Enzymes, transport, recognition, attachment, transduction
What is citolyse?
Cell burst due to the amount of water taken in
What is hemolysis?
Cytolosis (burst) of a red blood cell
What is hypotonic?
Decreased osmolality from plasma; cell draws water in.
What is isotonic?
Same osmolality as plasma
What is hypertonic?
Increased osmolality; pulls water out of a cell; Crenation occurs (dehydration)
Found in the cell membranes
Phospholipids, cholesterol, proteins, carbs
A bilayer of phospholipids
Plasma membranes
Phosphate heads are..
Polar and hydrophilic
Fatty acid tails are…
Nonpolar and hydrophobic
This creates a hydrophobic core to the plasma membrane
Phospholipid bilayer
This makes plasma membrane selectively permeable
Their structure- phospholipid bilayer
What molecules can easily pass through the membrane?
Oxygen, steroids, , carbon dioxide, alcohol- “small, noncharged, nonpolar”
What molecules need help passing through a membrane?
Water, ions, glucose, protein, electrolytes, amino acids- “large, charged, polar”
How does the lipid composition of a cell’s plasma membrane influence its behavior under different environmental conditions?
By affecting the membranes fluidity
What are the membrane protein functions:
Transporting, facilitating cell signaling by acting as a receptor, maintaining cell shape, cell recognition, carrying out enzymatic reactions depending on the specific protein type
Three types of protein junctions?
Adhering (organ), Tight - (waterproofing, skin) & Gap (communication/channels- heart)
Membrane transport=
Movement
Passive transport
Doesn’t require energy but needs a protein to help it get through a membrane
Passive transport
Doesn’t require energy but needs a protein to help it get through a membrane
Concentration gradient
Difference in concentrations of a substance between two areas
Simple diffusion
Doesn’t require energy/high to low concentration
Facilitated diffusion (Carrier and channel proteins)
Occurs without energy but needs protein to get to a cell
Osmosis
Diffusion
Movement of water molecules from high to low through semi-permeable membrane
Osmosis
Tonicity
Ability of a solution to change volume of cell by altering water content
Hypotonic
Solution with LOWER osmatic pressure/solute/decreased “muscle tone”
Isotonic
SAME water concentration/No net movement of water “muscle contraction”
Hypertonic
HIGHER tone, tension/higher concentration of solutes
Cytolosis
Pathologic dissolution/disintegration of cells “cell bursts”
Hemolysis
Breakdown of red blood cells “bursting of red blood cells”
Crenation
Cell shrinkage/dehydration
Primary active transport
Forcing molecules to move against where they wouldn’t naturally go through diffusion
Sodium/potassium (na*/k) pump
Membrane found in animal cells. Helps maintain equilibrium
Secondary active transport
Uses electrochemical energy to move molecules across cell membrane (co-transport)/relies on primary gradient
Symporter
Molecules moving in SAME direction
Anti-porter
Molecules moving in OPPOSITE direction
Vesicular
Move substances into or out of the cell
When water flows into a cell
Hypotonic
When water moves at equal rate
Isotonic
This occurs when water is pulled out of cells
Hypertonic
ATP/Damned up water
Primary active transport
Pumps (2) sodium out and (3) potassium in
Sodium potassium pump
Types of vesicular transport
Exocytosis, Pinocytosis, Phagocytosis and Receptor mediated endocytosis
This type of vesicular transport removes waste out of a cell
Exocytosis
Hormones, waste, neurotransmitters
Examples of exocytosis
This type of vesicular transport takes in fluid/ consumption “like a fine wine”
Pinocytosis
An example of Pinocytosis
Small intestines/nutrient rich
This type of vesicular transport sell in golf’s or eats large particles/non-specific solid
Phagocytosis
An example of phagocytosis
Bacteria, viruses, microvilli
This type of vesicular transport allows cells to absorb molecules like a “lock and key”
Receptor mediated endocytosis
Examples of receptor mediated endocytosis
Used by animals to bring cholesterol and certain hormones
How does solid concentration influence osmosis inside a cell?
Determining direction and rate of water movement across cell membrane
How does solid concentration influence osmosis outside of the cell?
It causes water to move out of the cell via osmosis
Against or up
Active (requires energy/atp)
Along or down/concentration gradient
Passive (doesn’t require energy but needs a protein to get through)
