Chapter 6: Tour of Cell Flashcards
Cell Theory
All organisms are made of one or more cell, cells are the basic unit of organization in all organisms, cells arise only by division of a previously existing cell
Light Microscopes
Pass light through a specimen and can magnify up to x1000. Can see mitochondria, nucleus, chloroplast
Scanning Electron Microscopes
Focus on a beam of electrons onto the surface of a specimen providing images that look 3D
Transmission Electron Microscope
Focus a beam of electrons through a specimen and allows resolution of the internal structures of the cells.
Cell Fractionation
Technique used to separate cells in terms of their major organelles. Allows scientists to study the organelles more closely and individually.
Basic features of all cells?
Plasma Membrane, Semifluid called cytosol, chromosomes made of DNA, Ribosomes
What is the difference between cytosol and cytoplasm?
Cytoplasm is a combination of cytosol and organelles. Cytoplasm is the “liquid” part of cytoplasm. There are NO organelles in cytosol!!
What is the plasma membrane made out of?
Phospholipid Bi-Layer. Hydrophilic head, hydrophobic tail.
Omnis Cellula e Cellula
All cells from cells
Why is Surface Area to Volume Ratio so important in cells?
for functionality. Cells require a constant transport of fluids, nutrients and waste across the cell. Having a larger ratio is better.
Why do eukaryotes have internal membranes that form their organelles?
to allow for multiple processes to go on at once
what is the protein that makes up chromosomes?
chromatin
What major process occurs in the nucleus?
DNA synthesis and RNA synthesis. (transcription and translation)
What process occurs in the nucleolus?
rRNA synthesis. rRNA + proteins = ribosome
What does the nuclear envelope do? And what does it consist of?
encloses the nucleus, separating it from the cytoplasm. Is a double membrane consisting of phospholipid bi-layer
function of nuclear pores?
regulate entry and exit of molecules from nucleus
function of nuclear lamina?
covers inside of INNER MEMBRANE of nucleus, holding the nucleus’ shape.
what is the nuclear lamina made of?
protein lamina
What are ribosomes made of?
rRNA and Proteins!
Ribosomes are…
NOT membrane bound organelles
What are the components of the endomembrane system?
Nuclear Envelope, Endoplasmic Reticulum, Golgi, Lysosomes, Vesicles + Vacuoles, Plasma Membrane
what is the function of the endomembrane system?
regulation of protein traffic and performs metabolic functions in the cell
NEG LVP
components of Endomembrane System
What is the endoplasmic reticulum (general) made of?
set of interconnected tubules and flattened membranes called cisternae
What does the ER membrane exactly do?
separates the internal compartment of the ER, called the ER lumen from the cytosol
What are the functions of the Smooth ER?
Synthesize lipids, detoxifies drugs and toxins, stores calcium ions.
Why does the nucleus only store SOME of the cells DNA in a eukaryotic cell?
because some DNA is housed in the mitochondrion and or chlorolpast
What is contained in the outer nuclear membrane?
Ribosomes
Functions of the Rough ER?
Protein synthesis, glycosylation, make new membrane for the cell, distribution of transport vesicles.
What is glycosylation?
adding carbohydrates to proteins after translation to form gylcoproteins
what are these so called “transport vesicles”?
membrane sacs carrying proteins and other molecules
why do the different sections of the golgi apparatus function differently?
They possess different structural polarity. The membranes of the cisternae differ in thickness and molecular composition
what does the “cis” side do in the golgi?
acts and the receiving end
what does the “trans” side do in the golgi?
acts as the shipping end
What are the primary functions of the golgi as a whole?
post transitional modification of glycoproteins. sorts and packages proteins
what is the function of lytic compartments?
to breakdown molecules by hydrolytic enzymes via hydrolysis
what are two main examples of lytic compartments?
lysosomes and lytic vacuoles
what is the function of the central vacuole in plant cells?
stores macromolecules, water, and ions
what is the function of the contractile vacuole found in many freshwater protists?
pumps excess water out
what is the function of the food vacuole, found in protists?
to ingest food. formed transiently by phagocytosis in proteins
what is the exception to cells breaking down their components?
DNA
what is the process called when cells break down and recycle their components?
Autophagy
how does autophagy take place?
damaged or needing to be recycled organelles are packaged into vesicles, and fuse with lysosomes to breakdown their components via hydrolysis.
What is the cellular cause of Tay-Sachs?
absence of lysosome(s), specifically ONE of the hydrolytic enzymes.
what process takes place in the mitochondria?
cellular respiration
what process takes place in the chlorplasts?
photosynthesis
what does the endosymbiont theory state?
early ancestors of all eukaryotic cells engulfed a non photosynthetic prokaryotic cell, resulting in an endosymbiont relationship. Then, the new eukaryotic cell with a mitochondria engulfed a cell with a chloroplast! REPEAT
What features among mitochondria and chloroplast are unique?
Double membranes, contain bacteria like ribosomes, circular DNA, grow and reproduce independtly
What are the fold in mitochondria called?
cristae
what is the pigment in chloroplasts called?
chlorphyll
what is the description of the main function of chloroplasts?
converts light energy into chemical energy
What are the membranes INSIDE of the chloroplast called? And their stacks?
Thylakoid Membrane. Granum are the stacks
What is the inner fluid of the chloroplast called?
stroma
what are the functions of peroxisomes?
detoxification, breakdown of fatty acids for energy
what is the byproduct of peroxisomes?
hydrogen peroxide (H2O2)
