Organelle/cell type from SLIDE DECK

Cell

The basic structural and functional unit of every organism.

Structures found in all cells

All cells are bound by a plasma membrane and contain cytosol, chromosomes, and ribosomes.

Prokaryotes

Cells in the domains Bacteria and Archaea; their DNA is in the nucleoid region, and they are generally smaller than eukaryotes.

Meaning of pro

Before.

Eukaryotes

Cells found in protists, fungi, animals, and plants; their DNA is in a nucleus, and they contain membrane-bound organelles.

Meaning of eu

True.

Organelles

Membrane-bound structures in eukaryotes.

Endomembrane organelles

Nuclear envelope, endoplasmic reticulum, Golgi complex, lysosomes, vesicles, vacuoles, and plasma membrane.

Energy organelles

Mitochondria and chloroplasts.

Compartmentalization

Allows different metabolic reactions to occur in different locations.

Benefits of compartmentalization

Increases surface area for reactions and prevents interfering reactions from occurring in the same location.

Plant-cell components

Chloroplasts, central vacuole, cell wall, and plasmodesmata.

Plant-cell energy category

Plant cells are described as photo-autotrophic.

Animal-cell components

Lysosomes, centrosomes, and flagella.

Animal-cell energy category

Animal cells are described as chemo-heterotrophic.

Structures shared by plant and animal cells

Nucleus, ER, Golgi body, mitochondria, cytoskeleton, vesicles, vacuoles, peroxisomes, nuclear envelope, and nucleolus.

Structures listed specifically for plant cells

Chloroplasts, plasmodesmata, and a large central vacuole.

Structures listed specifically for animal cells

Centrioles, gap junctions, tight junctions, lysosomes, cilia, and microvilli.

Structures found in all cells on the comparison diagram

Cell membrane, ribosomes, cytoplasm, and DNA or RNA.

Cell wall location on the comparison diagram

Listed as a structure shared by plant cells and prokaryotes.

Flagella location on the comparison diagram

Listed as a structure shared by animal cells and prokaryotes.

Prokaryotic-cell components

Nucleoid, pili, capsule, and plasmids.

Plasmodesma

Listed as a plant-cell component.

Gap junctions (connect cytoplasm of adjacent animal cells)

Listed as an animal-cell component.

Tight junctions

Listed as an animal-cell component.

Microvilli

Listed as an animal-cell component.

Pili

Listed as a prokaryotic-cell component.

Capsule

Listed as a prokaryotic-cell component.

Plasmids

Listed as prokaryotic-cell components.

Nucleus

Contains chromosomes, which hold genetic information.

Nuclear envelope

A double membrane that encloses the nucleus.

Nuclear pores

Regulate the entry and exit of materials.

Nucleolus

A dense region of the nucleus where ribosomal RNA is synthesized.

Ribosomal RNA formation

rRNA combines with proteins to form the large and small subunits of ribosomes.

Ribosomal subunits

Exit through nuclear pores and assemble into ribosomes.

Ribosome composition

Ribosomes are made of ribosomal RNA and protein.

Ribosome function

Ribosomes are the site of translation for protein synthesis.

Ribosomes and mRNA

Ribosomes translate messages found on mRNA into the primary structure of polypeptides.

Free ribosomes

Located in the cytosol; proteins made here generally function within the cytosol, such as enzymes.

Bound ribosomes

Attached to the ER or nuclear envelope; proteins made here can be secreted from the cell through transport vesicles.

Endoplasmic reticulum

A network of membranous sacs and tubes that helps maintain the cell’s shape.

Functions of the ER

Synthesizes membranes and keeps proteins formed in the rough ER separate from proteins made by free ribosomes.

Rough ER

Contains ribosomes attached to its membrane and performs protein synthesis.

Smooth ER

Contains no ribosomes; synthesizes lipids, metabolizes carbohydrates, and detoxifies the cell.

Golgi complex structure

Contains flattened membranous sacs called cisternae.

Golgi cisternae

Separate the sacs from the cytosol, and the individual cisternae are not connected.

Golgi directionality

The Golgi has a cis face and a trans face.

Cis face of the Golgi

Receives vesicles from the ER.

Trans face of the Golgi

Sends vesicles into the cytosol, to other locations, or to the plasma membrane for secretion.

Golgi complex function

Receives materials from the ER, folds and modifies cellular products, and packages proteins for trafficking.

Golgi and transport vesicles

The Golgi packages materials into new transport vesicles that exit the membrane through exocytosis.

Vesicles

Small membranous sacs that store, transport, or secrete materials around or out of cells.

Secretory vesicles

Fuse with the cell membrane to deliver membrane proteins or release secretory proteins.

Exocytosis

The process used when secretory vesicles fuse with the cell membrane.

Lysosomes

Membranous sacs containing about 50 kinds of hydrolytic enzymes produced by the Golgi.

Lysosome functions

Hydrolyze macromolecules, digest old cell parts and large food molecules, and help with programmed cell death.

Autophagy

Lysosomes recycle their own cell’s organic materials, allowing the cell to renew itself.

Peroxisomes

Membrane-bound metabolic compartments similar to lysosomes.

Peroxisomes in animals

Found in the liver and break down excess fatty acids into cholesterol, bile acids, and lipids for myelin sheaths.

Peroxisomes in plants

Found in seeds and break down fats to help the seeds germinate.

Vacuoles

Vesicles or sacs that store food, water, and waste and are selective in transport.

Animal-cell vacuoles

Store cell materials; they are abundant but smaller than plant-cell vacuoles.

Plant-cell vacuoles

Store water and nutrients, are important for turgor pressure, and are usually large and centrally located.

Endosymbiotic theory

Explains the similarities that mitochondria and chloroplasts have to prokaryotes.

Process described by endosymbiotic theory

An early eukaryotic cell engulfed a prokaryotic cell, which became an endosymbiont living inside another cell.

Evidence for endosymbiotic theory

Mitochondria and chloroplasts have double membranes, ribosomes, circular DNA, and are described in the deck as capable of functioning on their own.

Mitochondria

The site of cellular respiration.

Mitochondrial membranes

Mitochondria have a double membrane; the outer membrane is smooth, and the inner membrane has folds called cristae.

Cristae

Folds of the inner mitochondrial membrane that divide the mitochondrion into two internal compartments and increase surface area.

Intermembrane space

The space between the inner and outer mitochondrial membranes.

Mitochondrial matrix

The area enclosed by the inner mitochondrial membrane.

Contents of the mitochondrial matrix

Enzymes that catalyze cellular respiration and produce ATP, mitochondrial DNA, and ribosomes.

Krebs cycle location

The Krebs cycle occurs in the mitochondrial matrix.

Mitochondria and metabolic activity

The number of mitochondria in a cell correlates with the cell’s metabolic activity.

Cells with more mitochondria

Cells with high metabolic activity, such as cells that move or contract, have more mitochondria.

Chloroplasts

Specialized organelles in photosynthetic organisms and the site of photosynthesis.

Chlorophyll

The green pigment found in chloroplasts.

Thylakoids

Membranous sacs inside chloroplasts that can be organized into stacks called grana.

Grana

Stacks of thylakoids where light-dependent reactions occur.

Stroma

The fluid surrounding the thylakoids.

Calvin cycle location

The Calvin cycle occurs in the stroma.

Contents of the stroma

Chloroplast DNA, ribosomes, and enzymes.

Cytoskeleton

A network of fibers throughout the cytoplasm.

Cytoskeleton functions

Provides structural and mechanical support, anchors organelles, and allows vesicles, organelles, or the whole cell to move.

Cilia and flagella

Extensions of the cytoskeleton that allow cell motility.

Cytoskeleton and movement

Movement occurs when the cytoskeleton interacts with motor proteins.

Motor proteins

Use the cytoskeleton like highways to move materials and move when activated by ATP.

Motor-protein functions

Important in muscle contraction, cilia and flagella movement, and movement of vesicles inside the cell.

Pseudopods

False feet described as elongated microfilaments that help propel an amoeba forward.

Motor proteins and pseudopods

Motor proteins help drag the rest of an amoeba behind its pseudopods.

Three cytoskeleton fibers

Microtubules, microfilaments, and intermediate filaments.

Microtubules

Hollow rod-like structures made from the protein tubulin.

Microtubules and the centrosome

Microtubules grow from the centrosome, which assists in microtubule assembly.

Microtubule functions

Provide structural tracks for organelle movement, separate chromosomes during cell division, and assist with cell motility through cilia and flagella.

Microfilaments

Thin solid rods made from the protein actin.

Microfilament functions

Maintain cell shape, bear tension, assist with muscle contraction and cell motility, and help animal cells divide.

Actin and myosin

Actin works with myosin to cause a contraction.

Microfilaments during animal-cell division

Form the contractile ring of the cleavage furrow.

Intermediate filaments

Fibrous proteins made from varying subunits and described as permanent structural elements of cells.

Intermediate-filament stability

They are not assembled and broken down as quickly as microtubules and microfilaments.