Eukaryotic Cell

StructuresChapter 7.3

Cellular Boundaries

• ____________ membrane (aka cell membrane) is a flexible boundary of a cell– It is also a selectively permeable membrane

Cellular Boundaries

• Plant Cells, Fungi, Bacteria and some Protists have an additionally membrane called a _________________

– It is a fairly rigid structure located outside the plasma membrane

– It provides additional support and protection

The Cell Wall

• Forms an inflexible barrier that ___________ the cell and gives it __________

• Plant cell wall has carbohydrate ____________ (tough mesh of fibers)

• It does _______ select which molecules can enter into the cell

The Cell Wall

• Plants can have cell walls that are multiple layers– _____________ cell wall

develops in young plants– A ______________ cell

wall can develop in more mature plants

• Wood is an example of a secondary cell wall

The Nucleus and Cell Control

• __________ controls activity of the organelles– Has directions (blueprints) to make proteins

The Nucleus and Cell Control

• It is enclosed by a nuclear _____________, which is has a double membrane

• DNA is organized along with proteins into a fibrous material called _____________– Only when cells are preparing to divide, does

the chromatin coil up and condense to form _______________

2 Membranes on the nucleus

2 Membranes on the nucleus

Will turn into

chromosomes

when cell is

dividing

The Nucleus and Cell Control

• Within nucleus lies ____________

– Nucleolus makes ______________

• Ribosomes are the site where ___________ are made (using DNA instructions)

Ribosomes

• They are composed of ____ subunits.

• Some ribosomes are free & floating in the _____________(clear, gelatinous fluid inside cell) while others are attached to the endoplasmic reticulum.

• They help process instructions (DNA) from the nucleus and convert it into instructions for making a protein

The ENDOPLASMIC SYSTEM

• The nuclear envelope

• Endoplasmic reticulum

• Golgi apparatus

• Lysosomes

• Vacuoles

• Plasma membrane

Organelles For Assembly & Transport Of Proteins

• Endoplasmic Reticulum (_____) = site of cellular chemical reactions– Arranged like folded membranes in cytoplasm

Organelles For Assembly & Transport Of Proteins

• If ribosomes are attached to the surface of ER it is called ________ (Rough Endoplasmic Reticulum)

Organelles For Assembly & Transport Of Proteins

• ______ = Smooth Endoplasmic Reticulum no ribosomes attached

Smooth Endoplasmic Reticulum

• Synthesizes lipids (oils, phospholipids, & steroids)– Testes & ovaries are rich in

SER to make & secrete hormones

• Detoxify drugs and poisons in the liver cells

• Help trigger muscle contractions

Rough Endoplasmic Reticulum

• Uses attached ribosomes to make secretory proteins – Ex: insulin (proteins that are

released from the cell), glycoproteins (part of the plasma membrane)

– To transport proteins to other organelles

• Makes its own phospholipids membrane to be transferred by vesicles to other parts of the endomembrane system

Golgi Apparatus or Golgi Body

• After proteins are made, they are transferred to Golgi Apparatus or ____________– Golgi = center of

manufacturing, warehousing, sorting & shipping

– Products of the ER are modified, stored, and shipped to other destinations

Golgi Apparatus or Golgi Body

– Golgi apparatus = flattened stack of membranes (ex: pita bread)

– Golgi apparatus sorts proteins into packages and packs them into membrane-bound structures called _______________ to be sent to their destination

Organelles For Assembly & Transport Of Proteins

– Two poles of a Golgi stack are referred to as the _____ face and the _______ face

• Cis is located near the ______ and is the receiving end

• Trans is the opposite front that sends vesicles on their way

Vacuoles and storage

• Vacuoles = membrane bound compartments used for temporary _________ of materials– A vacuole is used to

store food, enzymes, waste products, and other materials

Vacuoles and storage

• Examples: – Food Vacuoles– Contractile Vacuoles

(pump excess water)– Central Vacuole (seen

in plants)

Lysosomes and recycling

• Lysosomes = organelles that contain __________ enzymes– Digest excess or worn out

organelles, food particles, and engulfed viruses or bacteria

– Can fuse with vacuoles and dispense their enzymes into the vacuole, digesting it contents.

Peroxisomes

• Contain enzymes that transfer hydrogen from substances to produce _________________as a by-product hence the name!

• Use oxygen to break fatty acids down

• Detoxify alcohol

• H2O2 is toxic to the cell, but it produces an enzyme that converts it to water

Peroxisomes

Chloroplasts and Energy

• Chloroplast belongs to a group of plant organelles called ___________– Plastids are used for

storage (storing starch, lipids, pigments)

• Ex: Amyloplast store starch (amylose), Chromoplast have pigments that give fruits & flowers their orange and yellow hues

Plastids

Chloroplasts and Energy

• Chloroplast have the pigment ___________ (gives it the green color, traps light energy)

Chloroplasts and Energy

• Chloroplast = cell organelles that capture ___________ energy and convert it into chemical energy for the plant to use

• Has double membrane

• Little stacks of membranous sacs (ex: poker chips) called ___________. Each individual sac is called a ____________

• The fluid outside the thylakoids is called ____________ (similar to cytoplasm)

• Found in plants & algae and used for the site of photosynthesis

Mitochondria and energy

• Mitochondria = membrane bound organelles in plant and animal cells that transform __________ for the cell– Site of “cellular respiration”

the process that generates ________from sugar (with the help of oxygen)

– Energy is stored in bonds of ATP which the cell organelles can access easily

• Found in nearly all eukaryotic cells

• Some cells have a single large mitochondrion or they can have hundreds

• Enclosed by two membranes (Inner & Outer)– Inner membrane is

convoluted with infoldings called ____________

Cytoskeleton

• Cytoskeleton = forms a framework for cell (like a ____________)

• Network of tiny rods and filaments

Cytoskeleton

• ________________ = thin, hollow cylinders made of proteins

• _______________ = smaller, solid, protein fibers• Maintain shape similar to poles keeping tent up

Centrioles

• Found in animal cells

• Occur in pairs

• Made up of ________________

• Play an important role in cell division

Cilia & Flagella

• Cilia and flagella are made of _____________ and aid in locomotion and feeding

• In unicellular organisms, cilia & flagella are the main means of locomotion

Cilia & Flagella

• Cilia = short, numerous _______-like projections– Occur in large

numbers on the cell surface

– Move more like oars in an alternating pattern

Cilia & Flagella

• Flagella = longer projections that move with a ________-like motion (usually only 1 or 2 flagella)

Prokaryotic vs Eukaryotic

• Prokaryotic cells (ex: bacteria) lack membrane-bound organelles

• The DNA is concentrated in a region called the ___________. No membrane separates this region from the rest of the cell.

• A eukaryotic cell has a true __________, bound by a nuclear envelope.

• The region between the nucleus and the plasma membrane is called the __________.

• Eukaryotic cells are generally much __________ than prokaryotic cells.