Cell Structure Flashcards
Typical cells range from ____ to ____ __ in ____
5 - 50 μ diameter
_____ ______can be extremely small or large enough to see with the unaided eye
special bacteria
What cell can be seen with the unaided eye?
Eggs
Despite differences in size and shape, at some
point all cells have ____ and a _____
DNA, Cell membrane
Plasma Membrane
Another name for cell membrane
What are the two types of cells?
Prokaryotes and Eukaryotes
What are prokaryotes?
Cells that are usually smaller and simpler than eukaryotes and do not separate their genetic material in a nucleus
What are some examples of prokaryotes?
Bacteria and Archea
Prokaryotes do not have
Membrane bound organelles (NO NUCLEUS) [have ribosomes]
Because prokaryotes do not have nuclei, where do they store their DNA
Nucleoid region
What are Eukaryotes?
Cells that are more complex than prokaryotes and contain dozens of internal membranes and structures (that are usually specialized)
Do eukaryotes have nuclei?
Yes
Examples of eukaryotes
Protists, unicellular/multicellular organisms
Organelles
little organs, act like specialized organs of the cell
What organelles do animal cells not have?
Chloroplasts, a central vacuole, tonoplast, cell wall, and plasmodesmata
What organelles do plant cells not have?
Lysosomes and centrioles
What are the three main parts of eukaryotes?
Cell membrane, cytoplasm, and nucleus
Cytoplasm
One of the main parts of the cell
Function is to provide “platform” where other organelles can stay
Nucleus
large membrane enclosed structure that contains DNA and controls many of the cell’s functions
What is the nucleus known as?
Office or control center of the cell
How many membranes does the nucleus? What are their names? (or its name)
2; the Nuclear Membrane or envelope (NAME FOR TWO COMBINED) is made of an inner and outer membrane
The nuclear membrane has thousands of ___ ___
nuclear pore complexes
What is the function of nuclear pore complexes?
Allow material such as proteins, DNA, and other molecules to move in and out of the nucleus
What is in the nucleus?
Nucleolus, chromatin, nuclear envelope, and nuclear pore complexes
What is the nucleolus?
Where ribosomes subunits are made -> located in the center of the nucleus
What is chromatin?
Chromatin is the complex of DNA that is bound to proteins that is found scattered in the nucleus around the nucleolus
What are chromosomes and where are they found?
Supercoiled chromatin
What are vacuoles?
Sac-like membrane enclosed structures that store material such as water, salts, proteins, carbohydrates, and ions.
Animal cells have ____ vacuole(s)
Plant cells have ____ vacuole (s)
many; one central
Why do plant cells have one central vacuole?
This central vacuole is filled with water and supports heavy structures (such as the cell wall) and increases rigidity
Contractile Vacuole
found in paramecium, pumps excess water out of cells because protists cannot stop the water that surrounds it from coming in
If plant cells lose water that is stored in their central vacuole, eventually the plant will ____ because..
lose its rigidity because the central vacuole no longer supports the cell wall
What are the parts of the vacuole?
Tonoplast - Membrane around central vacuole
Cell sap - fluid found in vacuoles
Lys means to
break down (hydroLYSis)
What are lysosomes?
break down lipids, carbohydrates, and other proteins into small molecules that can be used by the rest of the cell OR breaks down organelles that are not needed. lysosomes are VERY IMPORTANT because they take away clutter in cells that may potentially cause disease
Lysosomes are found in
all animal cells and some special plants
How do lysosomes work?
They break down material with hydrolytic (digestive) enzymes that they are filled with
Cyto means
cell
Cytoskeleton
givers cells their shape and internal organization, helps transport material throughout the cell, and aids in the movement of some cells that have a flagella or cilia
What is the cytoskeleton made of?
Protein filaments
The cytoskeleton is constantly
broken down and built back up
What are the three proteins that make up the cytokeleton?
Microfilaments, microtubules, and intermediate filaments
What are microfilaments?
Threadlike, form a strong flexible framework
What are microfilaments made of?
protein called actin
Microtubules
Largest protein that makes up the cytoskeleton
Maintain cell shape
Helps during mitosis by forming the mitotic spindle which helps separate chromosomes.
Help build cilia and flagella
Are like monorails and hold cells in place, or provides a track for them to move on. (specific)
Microtubules are made of
protein called tubulin
How are microtubules organized?
organized in 9+2 pattern meaning there are nine pairs of microtubules in a cilia or flagella
What are cilia and flagella?
Projections of the cell surface that help cells move rapidly throug hliquid
How are microtubules connected in the 9+2 pattern?
small CROSS BRIDGES between microtubules that use chemical energy to pull on each other.
What are intermediate filaments?
protein that holds together cells and makes up the nuclear lamina
What are intermediate filaments made of?
protein called keratin
List the three proteins that make up the cytoskeleton from smallest to largest in diameter
Microfilaments
Intermediate Filaments
Microtubules
Microtubules are ____ structures
hollow
What are ribosomes?
Small particles of RNA and protein found in cytoplasm of cells whose function is to make proteins
How many types of ribosomes are there?and what are they?
2; free ribosomes and bound ribosomes
What are free ribosomes?
ribosomes that make proteins that are used in the cell
What are bound ribosomes?
ribosomes that are bound to the rough ER and make proteins in the cell membrane or are exported from the cell
All ribosomes start as ____ ribosomes and return to being a __ ribosome after….
All ribosomes start as free ribosomes and return to being a free ribosome after being temporarily bound
What does a ribosome consist of?
A large subunit and a small subunit.
Amino acid, mRNA, tRNA, growing protein chain, RNA
Endoplasmic reticulum (ER)
Internal membrane system that assembles lipid components of cell membrane, proteins, and other materials that are exported
What is the ER made of?
Rough ER and Smooth ER
Rough ER
where proteins are synthesized –> it is called the rough ER because of ribosomes on its surface
How are proteins synthesized in the rough ER?
1) Newly made proteins leave ribosomes
2) Ribosomes are inserted into rough ER
3) Ribosomes are chemically modified so that they can perform their specific tasks
How are proteins chemically modified in the Rough ER?
Oligosaccharides are randomly attached to the hydroxyl group of the proteins to make a glycoprotein
Oligosaccharide
chain of 8-12 monosaccharides (carbohydrates)
Golgi Apparatus
Organelle that looks like a stack of flattened membranes that modifies, sorts, and packages proteins/other materials for storage or release from the cell.
How does the Golgi Apparatus sort proteins?
By changing the order of the monosaccharides on the oligosaccharide so that it can be recognized by other cells and can have a proper function.
How does the Golgi Apparatus sort proteins?
By changing the order of the monosaccharides on the oligosaccharide so that it can be recognized by other cells and can have a proper function.
Where do proteins go after the smooth ER?
Golgi Apparatus
What is the smooth ER?
Part of the ER whose main function is to create lipids and detoxification.
Where is the smooth ER located?
Attached to the nucleus
Where is the nucleus located?
At the center of the cell
How do proteins get from the rough/smooth ER
vesicles that pinch off
What are vesicles?
Are like temporary vesicles that MOVE stored contents into other organelles.
After is content is moved to a different organelle, the vesicle….
becomes a part of the organelle it transferred material to
What are the steps of the transfer of material with a vesicle?
1) Budding
2) Fusion
Look at diagram in notes
What are chloroplasts?
“Solar Power” plants whose main function is to capture the energy from the sunlight (light energy) and convert it into food that contains chemical energy (glucose)
Chloroplasts have their own ___
DNA
What do the chloroplasts consist of?
Inner membrane, outer membrane, stroma, granum, and thylakoid
What is the stroma?
The colorless fluid in the chloroplasts
What is granum?
Stacks of thylakoids
What are thylakoids?
Flattened circles that absorb sunlight and where photosynthesis takes place. It also contains chlorophyll, which is what makes plants green
What is the mitochondria?
“Power House of the Cell” which converts the chemical energy stored in food into compounds (glucose) that are more convenient for the cell to use (ATP)
What do chloroplasts perform?
photosynthesis
What do mitochondria perform?
cellular respiration
Mitochondria has its own ___
DNA, ribosomes, rna in its matrix
DNA is inherited from the ___ of the ____
cytoplasm, ovum (egg cell)
What is the cell wall?
Porous wall that surrounds the cell membrane of plant cells and supports, shapes, and protects the cell from lysing. The porous surface also allows water, oxygen, carbon dioxide,etc. to pass through
What are the parts of the mitochondria?
Outer membrane, inner membrane, matrix, cristae, and intermembrane space
Outer membrane of mitochondria
membrane/wall around mitochondria
inner membrane of mitochondria
membrane of matrix
matrix of mitochondria
space withing the inner membrane of the mitochondria
Cristae of mitochondria
Bends in the inner membrane of the mitochondria
Intermembrane space of mitochondria
space between inner and outer membrane of mitochondria
The cell wall is made of
cellulose
Only eukaryotes have cell walls.
(True or False)
False; Prokaryotes and eukaryotes have cell walls but are made of different things
Cell walls break against gravity
(True or False)
False; cell walls have enough rigidity to work against gravity
What are centrioles?
Organelles that main function is to organize spindle fibers and chromosomes during mitosis ONLY ANIMAL CELLS
What are centrioles made of?
Microtubules that form in 9 sets of 3
What is the cell membrane?
Organelle that regulates what enters and leaves the cell or protects and supports the cell
Cell membrane is also known as the
Fluid Mosaic Model
Why is the cell membrane called the fluid mosaic model?
It is named the fluid mosaic model because there are many molecules that make it look like a mosaic.
Cell membrane is made out of
phospholipids in a lipid bilayer (lipid bilayer gives cells its strong, flexible structure)
Phospholipid
lipid containing phosphate group
Properties of the phospholipids
have hydrophobic (water hating) tails and hydrophilic (water loving) heads
In the lipid bilayer, the ___ are on the outside and the __ are on the inside
heads; tails
Why are the phospholipids assembled the way that they are assembled in the lipid bilayer?
The tails cluster together, and the heads cluster together on the outside because they are attracted to water/other liquids that cells may be in
The cell membrane is ______ ________
selectively permeable
Selectively Permeable
membranes that allow some substances to pass through and not others -> this is usually caused by size
What is in the fluid mosaic model?
Proteins (such as channels/pumps that help material move across the membrane), carbohydrates (allow cells to recognize each other), cholesterol (odd shape keeps the membrane from freezing when it is cold so cells don’t die)
The heads of phospholipids are…
polar (this is because the tops of the heads have a slight positive charge and the bottom has a slight negative charge )
The tails of phospholipids are…
non polar
Phospholipids are all ___ to prevent them from ____
bent; freezing (they are bent so that they are unsaturated with a carbon-carbon double bond)
What makes up phospholipids? (not head +tail)
Choline (top of head), phosphate group (bottom of head), and glycerol (fatty acid chains as tails)
All cells must carry what
chromosomes
another way to say cell membrane
plasma membrane
what is usually bigger pro or eukaryores
eukaryotes
what is the main kingdom of prokaryores
archea
cytoplasm
all the organelles and the jelly
cytosol
fluid
How do prokaryotes move
they usually have cilia or flagellum
which microscope allows you to see internal structure
transmission microscopes
what do specimen have to be to be able to be seen by a transmission microscope
super super thin cut
what are the membranes of the nucleus made of
phospholipids
What is inside the central vacuole
water and other small organic material or pigmentation
Microfilaments sometimes make what
microvilli
Is the gel or sol thicker and why
the gel is thicker because there is more actin subunits than in the sol
Microfilaments purpose
allows amoebas and other cells to crawl across surfaces by assembly and disassembly which causes cytoplasmic movement.
Pinches in membrane for mitosis
Involved in muscle contractions
cell motility
changes the cells shape
what type of cells are centrosomes in
animal and plant
Centrosomes are used for movement when
when theres 2
How are basal bodies formed
9 sets of 3 microtubules
What are basal bodies for
for stabilizing the cilia and flagella
how do cilia move
oar like
how does flagellum move
undulate
Which face does the golgi apparatus recieve and send off vesicles respectively
cis and then trans
how does the golgi apparatus modify proteins
by adding a glycoprotein to sort them
where is sorting of proteins done in the golgi apparatus
in the cisternae
how does the cell wall prevent cells from bursting
it prevents too much water from coming in
do cell walls replace cell membranes
NO NEVER NO NO NO NO NO
Nuclear Lamina
network of intermediate fibers inside nuclear envelope –> like a framework can be built and broken pretty easily
Why is the nucleus known as the control center of the cell
because it has the DNA which codes for RNA which codes for proteins, proteins = enzymes, enzymes = processes
Nuclear matrix
protein filaments that go throughout the nucleus for support
are free and bound ribosomes structurally different
no
Endomembrane system
organelles that are all membrane bound and have the same membranes so that pieces of each of them can pick up and move to another one in the system
what is the common membrane of the endomembrane system made of
phospholipids
what organelles make up the endomembrane system
golgi apparatus
vesicles
cell membrane
endoplasmic reticulum (smooth + rough)
vacuoles
lysosomes
endomembrane system purpose
protein synthesis, organelle trapnsport, movement, metabolism, etc.
Vesicles
sacs of membrane for transport of proteins, lipids, etc. to membrane + beyond
what is the difference between the smooth er and the rough er
the rough makes proteins (from ribosomes on surface) and the smooth makes lipids
where is the rough er located
on the nucleus
where is the smooth er located
on the rough
chromosomes
DNA organized into discrete units; contains one long DNA molecule with proteins (histones) –> coiled up so it fits in the nucleus
how many chromosomes do hoomans have
46
Chromatin
the complex of DNA and protein that makes up chromsones (not coiled up)
Pore complexes are made of
proteins
tubules
small microscopic tubes that are hollow inside
cisternae
liquid filled sacs
transport vesicles
piece from ER that bulges off and moves to golgi
what happens if a lysosome lyses in a cell
enzymes denature bc theyre not in the right conditions bc the cytosol is almost neutral and lysosomes have a pH of 5
autophagy
random bad/dead organelles in cytosol get surrounded by membrane and bind with a lysosome to digest
hydrolytic
done with hydrolysis
apoptosis
fr me :P
hydrolytic processes
break down macromolecules bc of excess lysing
Glycoprotein
secretory proteins with a small chain of monosacchardies attached to them (function is to identify cells by putting them in the cell membrane)
where is the cis face of the golgi apparatus
on the er
Phagocytosis
unicellular organisms and eukaryotes that eat organisms that are smaller than them by engulfing them and fusing with a lysosome
cell motility
changes in cell location and cell part movement which usually requires motor proteins
contractile vacuoles
star thingies that shoot out water in paramecium and amoeba
food vacuoles
digests things and does phagocytosis
plastids
storage organelles
motor protein
proteins that aid organelles/cell/cytosol to move around/in the cell
how do motor proteins work for microtubles and organelles
the organelle binds ot the receptor for motor molecule
motor molecule gets ADP and gets phosphorylated so the shape changes and it moves up and pulls the rest with it and the repeat
how do motor proteins work for microtubles and microtubules
microtubules attach to other microtubules with motor proteins
motor molecule gets ADP and gets phosphorylated so the shape changes and it moves up and pulls the rest with it and the repeat
Dimer
a molecule made of 2 subunits
Centrosome
a region locatated near the nucleus where microtubules grow out of
centrosomes are made of what
2 centrioles
what is the structure of a basal body
9+0
what is the structure of a flagellum
9+2 –> 9 doublets in a ring with 2 in the middle
Dyneins
motor molecules (proteins) that are attached to the outside of microtubule doubles (they usually have 2 feet and they use ATP)
are microfilaments easy to break down and build up
no
what is the structure of intermediate filaments like in animal cellls
scattered
what is the structure of intermediate filaments like in plant cellls
cell wall structured
cortex
the outer cytoplasmic layer of a cell (supported by network of microfilaments)
myosin purpose
interacts with actin to contract muscles
Pseudopodia
false feet that are cellular extensions which aid in ameboid movement
Cytoplasmic streaming
circular flow of cytoplasm around the central vacuole which speeds up the distribution of materials and nutrients within the cell because of pressure (the gel around (thick) pressures the sol (skinny ol legends) into moving fast fast)
Cell wall is made with what enzye
cellulose synthase
Primary cell wall
wall of young plant that is flexible and thin
Middle Lamella
the sticky stuff in between 2 adjacent plant cells
what is the middle lamella made of
sticky polysacchardies called pectins
secondary cell wall
wall between the plasma membrane and the primary cell wall that has a strong and duravke double matrix to provide protection and support
puedes tener multiples cell walls
SUI
ECM
extra cellular matrix
is the ECM the same in every cell
no
Plasmodesmata
the channels that connect cells by joining the internal chemical environments of adgacent cells ONLY PLANT
Proteoglycan
more carb than protein – weaves around collagen
collagen
most abundant glycoprotein in animal cells
glycoprotein
protein with sugar
fibronectin
glycoproteins that bind to integrins on cell that allow other cells to bind to the cell
integrins
cell surface prooteins that glycoproteins can bind to and they also send signals between the ECM and the cytoskeleton + regulate cell behavior cheically + mechanically
tight junctions
intercellular junction whose purpose is to not let fluid into animal cells – it does this because its an integral protein and binds to the protein of another cell which makes this water proof seal
desmosomes
intermediate filaments that bind together to hold difference cells together (uses keratin)
gap junctions
integral protein channel that spreads through 2 cell membranes which allows certain stuff to pass through
gap junction aka
communication junction
