Cells Flashcards
Module 1
What is the three concepts of cell theory
1.) all organisms are made of cells
2.) cells are a the fundamental unit of life
3.) all cells come from pre-existing cells
the fluid mosaic model of the cell membrane states what
1.) bilayer
2.) phospholipids
3.) cholesterol
4.) proteins
5.) lipids
6.) dynamic (like a fluid)
What is a micelle
ball-shaped cell that affects the fluidity of plasmid membranes
This structure’s characteristics include regulating the temperature, length of non-polar tails, additional post-transitional modifications and have single/double bonds
lipids
T/F the head of a phospholipid is hydrophobic
False: it is hydroPHILIC
What does FRAP do?
Fluorescence Recovery After Photobleading shows that proteins move freely in the membrane
What components of a phospholipid is hydrophilic
the head consisting of choline, phosphate and a glycerol backbone
T/F Fatty acid chains are hydrophilic
False: they are hydrophobic
What is the importance of cholesterol in animal cells
it is amphipathic (hydrophilic and hydrophobic parts) and reduces membrane fluidity at normal temperatures
T/F all membrane proteins are classified as integral peripheral proteins
True
this membrane protein is described as transmembrane proteins, span the entire membrane, are permanently associated with the cell membrane and cannot be separated from membrane
Integral membrane protein
this protein is described as temporarily associated with internal or external side of the cell
Peripheral membrane protein
T/F the cell membrane is impermeable
False: it is selectively permeable and allows some molecules in/out
What is passive transport
requires no energy/work to move; diffusion
Difference between simple and facilitated diffusion
simple:
- high concentration to low concentration via concentration gradient
facilitated:
- move via channels in the membrane (passively)
This type of transport requires ATP for a channel to activate and/or will move molecules against the concentration gradient
active transport
Describe the properties of a prokaryote
- has no nucleus
- transcription and translation occurs in the cytoplasm
- hopanoids in the cell membrane
- small
- no organelles
describe the properties of a eukaryote
- has a nucleus
- transcription occurs in the nucleus
- translation occurs in the cytoplasm
- sterols (cholesterol) in the cell membrane
- larger than prokaryotes
- has organelles
What is the purpose of the endomembrane
has two compartments; one within the organelles and one outside the organelles. the separation allows for specific functions to take place in/out of the membrane
vesicles allow for communication between the organelles
T/F the smooth endoplasmic reticulum is associated with ribosomes which synthesize proteins
False: it’s the ROUGH endoplasmic reticulum
T/F the smooth endoplasmic reticulum is the primary site of lipid synthesis
True
T/F small molecules can diffuse through the nuclear envelope but larger proteins and RNA require active transport
True
What is the purpose of the golgi apparatus?
receives proteins and lipids from the endoplasmic reticulum, modifies then sorts them to other organelles, the plasma membrane and the cell exterior
What are pores?
protein openings in the nuclear envelope
What do lysosomes do?
receive enzymes from golgi apparatus that then breakdown macromolecules.
the protein pumps help maintain pH
T/F the mitochondria contains its own genomes
True
Describe chloroplasts
gain their energy from the sun which then synthesize into simple sugars (photosynthesis). has internal membrane-bound compartments called thylakoid where the pigments are found
what is the organization of the bio system?
cells organized into tissues
tissues organized into organs
organs organized into systems
systems form organisms
T/F a tissue is a collection of cells that work together to perform a specific function
True
What does a cell junction do
connects cells to other cells or to the basal lamina and are reinforced by the cytoskeleton
This is a connective tissue with few fibroblasts and a large extracellular matrix
dermis
this tissue is water resistant, a protective layer, with epithelial cells and melanocytes
epidermis
name the skin structure from outermost to innermost
1.) lumen
2.) epithelial tissue
3.) basal lamina
4.) connective tissue
This functions to determine the shape of a cell
cytoskeleton
This is involved in cell shape, cell movement, cell division, vesicle transport and organelle arrangement
Mircotubule (the one that looks like a firework)
T/F Microtubules are formed by tubulin dimers
true
What are the properties of a microfilament
aids cell shape, cell movement, cell division, vesicle transport and muscle contraction
has a double helix of actin molecules
surrounds the edge of filament
T/F neurons are intermediate filaments in the nucleus
False: lamins are intermediate filaments in the nucleus
What probably has a defect if your skin is less resistant to physical stress
intermediate filaments
What are tight junctions
they prevent the passage of materials in between cells (create a seal)
proteins = claudins and occludins
What are the anchoring types of cell junctions
1.) adherens junctions
2.) desmosomes
3.) hemidesmosomes
Gap junctions and plasmodesma are what kinds of cell junctions
communication
T/F a tight junction is a barrier type of cell junction
True
Difference between gap junctions and plasmodesmas
gap junctions = communication between cells in animals
plasmadesmas = communication between cells in plants
cadherins are major components in
adherens junction and desmosome
integrins are major components in
hemidemsosome
Intermediate filaments are the cytoskeleton attachment in
desmosome and hemidesmosome
T/F cell-cell adhesion is the primary function of hemidesmosomes
False: it is a primary function for adherens junctions and desmosomes
T/F the extracellular matrix provides structural support and information cues for cells
True
What is the most abundant protein in the extracellular matrix in animals
collagen
