Unit 2 cells Flashcards
What is the structure and function of the Golgi Complex
Structure: Rows of flattened membrane sacs (bubbles)
Function: processes, stories, and packages proteins
What is the structure and function of cytoplasm
Structure: Thick solution (clear jelly-like fluid)
Function: holds things in place and surface area for chemical reactions
What is the structure and function of ribosomes
Structure: tiny organelles, not membrane-bound, contain rRNA and protein, bond to ER or free float in cytoplasm
function: protein synthesis
What is the structure and function of lysosomes
Structure: Small, spherical, membrane-bound (1 membrane)
function: breaks down/digests certain materials
What is the structure and function of chloroplast
structure: oval-shaped, 2 membranes (inner and outer), stacks
function: converts light energy into sugar (ATP + sugar production)
What is the structure and function of the mitochondria
structure: small organelle, 2 membranes (inner called cristae folds to increase surface area for the electron transport)
function: produces energy
What is the structure and function of the smooth endoplasmic reticulum
structure: rows of flattened membrane sacs without ribosomes
function: Network of tubes, transports materials
What is the structure and function of the rough endoplasmic reticulum
structure: rows of flattened membrane sacs with ribosomes
function: Network of tubes, that help make and process proteins
What is the structure and function of the vacuole
structure: small or large bubble surrounded by 1 membrane
function: stores food, water waste
What is the structure and function of the nucleus?
structure: double membrane, large, round, surrounded by nuclear envelope, nuclear membrane + chromosomes
function: control center, regulates
What is the structure and function of the nucleolus
structure: composed of RNA proteins, round
function: assembles the cells ribosomes
What is the structure and function of the cell membrane
structure: Phospholipid bilayer
function: Separates the internal from the external, regulates what goes in and out of the cell
what is turgor pressure?
what cell relies on it?
An intercellular force, usually caused by water pushing up against the plasma membrane and cell wall
plant cells rely on it
How do subcellular components and organelles interact and contribute to the function of the cell?
Subcellular components and organelles interact to support cell function. The ER, mitochondria, lysosomes, and vacuoles, each have specialized functions that occur within their membrane-enclosed structures which increases the efficiency of the cell to perform chemical reactions and store materials.
What are the structural features of a cell that allow organisms to capture, store, and use energy?
Chloroplasts and mitochondria are structural features of eukaryotic cells that allow organisms to capture, store, and use energy. The folding of the inner membrane in both these structures increases the surface area which allows for more ATP to be synthesized.
why are cells are small
what happens to the surface area as the cell gets larger?
Smaller cells typically have a higher surface area-to-volume ratio and more efficient exchange of materials with the environment. because moving materials (waste, nutrients) in and out of the cell gets harder the larger the cell is.
it decreases
What are some examples of structural modifications of cells that increase surface area?
As cell volume increases or a cell becomes specialized for transport across its surface, structural modifications such as membrane folds are necessary to adequately exchange molecules from or into the environment.
How does the surface area to volume ratio effect the rate of heat exchange with the environment?
As organisms increase in size, their surface area-to-volume ratio decreases making it harder to release heat energy and adaptations may improve an organism’s efficiency in doing so.
How are specialized structures and strategies used by cells and organisms for the efficient exchange of molecules with the environment?
Cells and organisms use specialized exchange surfaces (e.g., stomatal openings on the surface of a leaf)
How does passive and active transport move molecules across the membrane?
movement of molecules (high to low) doesn’t require ATP
Movement of molecules and or ions (low to high) requires ATP, rely on carrier proteins called pumps
How do large molecules move into and out of the cell?
endocytosis and exocytosis
what are the 2 types of passive transport
Diffusion: movement of molecules from high to low, small non-polar molecules
facilitated diffusion: movement of molecules from high to low, large polar molecules allows hydrophilic and ions to travel through the membrane
phagocytosis?
pinocytosis?
receptor-mediated endocytosis?
the cell takes in large particles
the cell takes in liquid
proteins on the cell membrane are used to capture specific target molecules
What does hypotonic mean?
Water moves into the cell, Cells swell, can burst, turgid
The bars of the cell is less then the solution
Cell Solution
Y < Y
What does isotonic mean
Flaccid, equilibrium with the cell and the solution
Y=Y
What does hypertonic mean ?
The solution travels out of the cell, cells shrink, plasmolyse,
The number of bars of the cell has to be greater then the solution
Cell Solution
Y > Y
What is osmosis
the movement of water across a semipermeable membrane from an area of high water concentration to an area of lower water concentration.
Why are inner membranes usually folded? What does this allow?
Allows more surface area without increasing volume. Increases Metabolism (every chemical reaction in your body)
List the membrane bound organelles
Mitochondria
Lysosomes
Nucleus
Vacuoles
Smooth and rough ER
Golgi apparatus
Cell membrane
Chloroplast
Golgi vesicle
What organelles have membranes on their inside?
Mitochondria
Chloroplast
Nucleus
How do membranes help the efficiency of reactions occurring in the mitochondria, chloroplast and nucleus?
Increases surface area for reactions to occur
More embedded proteins for reactions
what is cotransport? what are the 2 types of co-transport?
secondary active transport that uses energy to transport two different ions across the membrane
Symport: 2 different ions are transported in the same direction
Antiport: 2 different ions transported in the opposite direction
Why are membrane proteins required for diffusion of certain molecules?
Membrane proteins are required for facilitated diffusion of charged and large polar molecules through a membrane.
How do large quantities of water move across the membrane?
Large quantities of water pass through aquaporins.
How do membranes become polarized?
Membranes become polarized by movement of ions across the membrane.
What molecules are necessary for active transport to occur?
what are the three types?
Membrane proteins are necessary for active transport.
Channel proteins: act’s like a pore in the membrane that lets water molecules or small ions through quickly.
Gate proteins: opens a “gate,” allowing a molecule to pass through the membrane.
carrier proteins: is specific for an ion, molecule, or group of substances by expanding the membrane and changing shape.
How does Na+/K+ ATPase contribute to membrane potential?
The Na/K ATPase contributes to the maintenance of the membrane potential.
na+ pumped out
k+ pumped in
How is water passively transported across a membrane?
Water is transported in small amounts across the membrane by simple diffusion and in large amounts via facilitated diffusion through aquaporins embedded in the membrane.
What are some examples of membrane-bound organelles in eukarvotic cells that compartmentalize intracellular reactions?
Eukarvotic cells contain various membrane-bound organelles including, but not limited to; the ER, Golgi complex, lysosomes, mitochondria, and chloroplasts. These structures compartmentalize intracellular processes and enzymatic reactions increasing the efficiency of cellular function.
How do internal membranes facilitate cellular processes?
Internal membranes facilitate cellular processes by minimizing competing interactions and by increasing surface areas where reactions can occur.
How might a change in the internal membranes or membrane-bound organelles effect the ability of eukaryotic cells to perform necessary functions?
Loss of these intracellular compartments or changes to the unique internal surfaces and environments within membrane-bound organelles may hinder proper cell function.
How do organisms maintain water balance?
Osmoregulation maintains water balance and allows organisms to control their internal solute composition/water potential.
