List the components of cell theory
- All living things are composed of cells.
- Cells are the basic unit of structure and function in living things.
- All cells come from preexisting cells.
Describe the range of cell size
Microscopic to the size of an ostrich egg yolk
How does a light microscope work?
visible light passes through a specimen and then through glass lenses, which magnify the image
How do scanning electron microscopes (SEMs) work?
they focus a beam of electrons onto the surface of a specimen, providing images that look 3-D
How do transmission electron microscopes (TEMs) work?
they focus a beam of electrons through a specimen
What is TEM mainly used to study?
the internal structure of cells
What does cell fractionation do?
takes cells apart and separates the major organelles from one another
Describe eukaryotes
- found in animals, plants, protists, fungi
- have a nucleus bound by an envelope
- have membrane bound organelles
- large cells
Describe prokaryotes
- bacteria
- No nucleus
- have a nucleoid
- No membrane bound organelles.
- Small cells
What is a nucleoid?
an unbound region where their DNA is found
Define organelles
cell structures with specialized functions
Describe the cell membrane
organelle that regulates what comes in and out of the cell, provides protection, and support.
What makes up the structure of the cell membrane?
phospholipid bilayer
Is the phospholipid bilayer head hydrophilic or hydrophobic?
hydrophilic
Is the phospholipid bilayer tail hydrophilic or hydrophobic?
hydrophobic
Where is the cell wall?
surrounds cell membrane
What is the cell wall made of?
cellulose
What is the cell wall’s purpose?
adds extra support
Where is the nucleus located?
the center of the cell
What does the nucleus contain?
DNA
The nucleus is enclosed by what?
nuclear envelope
Describe the nuclear envelope
made of a lipid bilayer. has pores
Describe the nucleolus
inside the nucleus. Makes ribosomal RNA that form ribosomes.
Where is the cytoplasm?
in between cell membrane and nucleus
The cytoplasm is made of a ______ ______ and a liquid called _______.
fiber matrix; cytosol
What is the function of the cytoplasm?
holds organelles in place
What does the mitochondria do?
release energy stored in glucose in the form of ATP through cell respiration
Describe the layout of the mitochondria
Double membrane (inner and outer)
The inner membrane of the mitochondria has folds called ______
cristae
The cristae form the _____________ ______ and the ______ _________ ______
mitochondrial matrix; inner membrane space.
What do plastids do?
store materials in plants
What do chloroplasts do?
make glucose from sunlight through photosynthesis
Chloroplasts contain the pigment __________ that makes plants green
chlorophyll
Describe the thylakoid
discs containing chlorophyll stacked in granum
Stroma
fluid in the space outside the granum
What do ribosomes do?
make proteins
What does the endoplasmic reticulum (ER) do?
makes and transports materials through the cell in vesicles
Describe the smooth ER
- makes and transports lipids and carbohydrates
- detoxes the cell
- stores ions for later use
Describe the rough ER
contains, ribosomes to make and transport proteins (gives it its rough look)
What does the golgi apparatus do?
Labels, packages, sorts and sends molecules from the ER out of cells in vesicles.
Describe lysosomes
membrane sacs filled with enzymes that break down materials (food or old organelles)
Lysosomes will merge with ____ _________ to break down food or carry out phagocytosis
food vacuoles
Describe phagocytosis
When the lysosomes engulf an old organelle to digest and recycle it.
Describe peroxisomes
they are like mini lysosmes that contain an enzyme called catalase that converts peroxide in to water and oxygen.
What does the vacuole do?
store materials in the cell
Plants have what type of vacuole?
large central vacuole
Animals have what type of vacuole?
small scattered vacuoles
Describe the endomembrane system
All connected by membrane or vesicles: Nuclear envelope Rough ER Smooth ER Golgi Lysosomes Vacuoles
Describe microtubules compared to the other cytoskeleton fibers’ size
thickest
What do the microtubules do?
help separate cells during cell division, make up flagellum, and guide moving vesicles like a train track
Describe intermediate filaments compared to the other cytoskeleton fibers’ size
middle size
What do intermediate filaments do?
anchor organelles and maintain cell shape
Microfilaments are also called _____ __________
actin filaments
Describe microfilaments compared to the other cytoskeleton fibers’ size
thinnest
What do microfilaments do?
help with muscle contraction
In muscle cells, thousands of actin filaments are arranged how?
parallel to one another
What are the types of cell junctions
Plasmodesmata
Gap Junctions
Desmosomes
Tight Junctions
Describe plasmodesmata
pores in the cell walls between plant cells
Descrive gap junctions
pores in the membranes between animal cells
Describe desmosomes
anchors that hold cells together
Describe tight junctions
tightly pressed cells to seal fluid out
What are cilia?
tiny hairs on the outside of cells that assist with movement
What are flagella?
large whip-like tail that assists with movement
What do centrosomes do?
assemble long microtubules out of proteins
What is the ER membrane made out of?
phospholipid bilayer
How does the Smooth ER detoxify toxins?
by adding a carboxyl group to toxins which makes the them soluble in water
Where are ribosomes found?
floating freely throughout the cytoplasm or attached to the nuclear envelope
How to ribosomes make proteins?
they assemble amino acids into polypeptides
How do ribosomes, the ER, and Golgi apparatus all interact?
as the ribosome builds an amino acid chain, the chain is pushed into the ER. When this protein chain is complete, the ER pinches it off and sends it to the Golgi apparatus
What do the Golgi bodies do?
- cut up large proteins into smaller hormones
- combine proteins with carbohydrates to make various molecules
What is chromatin?
weblike substance that gathers into rob-shaped chromosomes for cell division
