Unit 2 Eukaryotic Cells and Cell Organelles

What are all organisms on Earth believed to have descended from?

A common ancestral cell about 3.5 billion years ago

When did eukaryotic cells emerge?

About 3.5 billion years ago

What did endosymbiotic theory state?

That eukaryotic cells emerged when once free-living prokaryotes took up permanent residence inside other larger prokaryotic cells

What did the once free-living prokaryotes of endosymbiotic theory become?

Mitochondria and chloroplasts

What did an early prokaryotic ancestor of eukaryotic cells engulf?

An aerobic prokaryotic cell

What formed when an early prokaryotic ancestor of eukaryotic cells engulfed an aerobic prokaryotic cell?

A mutually beneficial symbiotic relationship between the two

What was the aerobic prokaryotic cell able to perform?

Aerobic cell respiration

What did aerobic cell respiration provide?

Energy to the cell that engulfed the aerobic prokaryotic cell

What would large cells provide in exchange for the energy provided by aerobic prokaryotic cells?

Nutrients and other materials

What did the beneficial symbiotic relationship between early prokaryotic ancestors of eukaryotic cells and aerobic prokaryotic cells evolve to the point of?

A full dependency between the two cells for survival

What would the aerobic prokaryotic cell that early prokaryotic ancestors of eukaryotic cells engulfed become?

Modern-day mitochondria organelle found in all eukaryotes

What may one of these mitochondria-containing cells have engulfed, forming another mutually beneficial symbiotic relationship?

A photosynthetic prokaryote

What would the cell that mitochondria-containing cells engulfed become?

Modern-day chloroplasts found in plants cells

What are the double membrane structures of mitochondria and chloroplasts consistent with?

What happens when cells engulf other cells or substances

What are the inner membranes with enzymes and transport mechanisms of mitochondria and chloroplasts similar to?

Plasma membranes of living prokaryotes

Mitochondria and chloroplasts are not autonomous.

False

How do mitochondria and chloroplasts grow and reproduce within the cell?

By a splitting process similar to prokaryotes

What kind of DNA do mitochondria and chloroplasts contain?

Circular DNA without histones or large amounts of other proteins

What is the DNA of mitochondria and chloroplasts similar to?

Bacterial chromosomes

What is the cellular machinery of mitochondria and chloroplasts needed to do?

Make proteins from DNA

Ribosomes are more similar to cytoplasmic ribosomes of eukaryotic cells than prokaryotic ribosomes.

False

What do eukaryotic cells contain?

A membrane-bound nucleus and internal structures bound by membrane

What kind of DNA do eukaryotes have?

Linear DNA

What are internal structures bound by a membrane called?

Organelles

What are organelles?

Specialized structures that work together to respond to stimuli and efficiently carry out necessary processes

What are most eukaryotes?

Multicelluar

What are examples of unicellular eukaryotes?

Yeast, algae, and protists

What are examples of eukaryotes?

Animals, plants, fungi, and protists

What structures are unique to plant cells?

Cell walls made of cellulose, chloroplasts, and large central vacuoles

What structures are unique to animal cells?

Flagella (can be in some prokaryotes), cilia, centrosomes with centrioles, and lysosomes

What is a unique structure of fungal cells?

Cell wall made of chitin or other polymers

The cell wall of fungal cells can sometimes be made of cellulose.

False

What kind of cells may be multinucleate?

Fungal cells

Why can fungal cells not photosynthesize?

They lack chloroplasts or other plastids so they do not have pigments

How do fungal cells get food?

By absorbing it from their environment

What are cells the basic unit of?

Life

When added together, what creates life?

Cytoplasm, all organelles, and membrane

How many cells are organisms made of?

One or more

What are the different shapes and sizes of cells dependent on?

Their function

About how many cells does the human body consist of?

200

What is the idea of biogenesis?

Cells come from other preexisting cells

What are the common features/organelles of all cells?

DNA/chromosomes, cell/plasma membrane, cytoplasm, and ribosomes

What are chromosomes?

Genetic material which contains all the information needed for growth, development, functioning, and reproduction

What is the cell membrane also known as?

The plasma membrane

What does the cell membrane separate?

The cellular components from the external environment

What does the cell membrane control?

What enters and exits the cell

What is the cell membrane?

A semipermeable phospholipid bilayer with embedded proteins

What are some additional things the cell membrane contains?

Carbohydrates and cholesterol

What is the cytoplasm?

A semifluid substance that fills the inside of the cells

What is cytosol?

Water/fluid portion of the cytoplasm

What does the cytoplasm contain?

Particulates

What are particulates?

Dissolved enzymes, proteins, nucleic acids, glucose, ions, and minerals

What are the functions of the cytoplasm?

Fills the cell to give support and structure to the cell and organelles and is the site of most chemical reactions

What are ribosomes?

Small structures made of ribosomal RNA and proteins

How many subunits to ribosomes have?

Two

What are the subunits of ribosomes?

A large and small one

Ribosomes are not bound by a membrane.

True

Why do ribosomes carry out?

Protein synthesis

How do ribosomes carry out protein synthesis?

By linking amino acids together using the information from DNA to form proteins

Where can ribosomes be found?

The cytoplasm and rough endoplasmic reticulum (RER)

What kind of ribosomes are found in the cytoplasm?

Free ribosomes

What do the ribosomes of the cytoplasm do?

Make proteins that function within the cytoplasm of the cell

What kind of ribosomes are found in the rough endoplasmic reticulum?

Attached ribosomes

What do the ribosomes of the rough endoplasmic reticulum do?

Make proteins for export and incorporation into cell membrane or enzymes for lysosomes

What do energy organelles do?

Convert energy from one form to another in a cell

What are the energy organelles of plant cells?

Chloroplasts and mitochondria

What is the energy organelle of animal and fungal cells?

Mitochondria

What do chloroplasts and mitochondria both contain?

Double membrane, circular DNA, and ribosomes

Why do the highly folded inner membrane of chloroplasts and mitochondria do?

Increase surface area for chemical reactions

What carries out aerobic cellular respiration?

Mitochondria

What does the mitochondria convert chemical energy in sugars/organic compounds into?

Chemical energy of ATP

What is the name for the folds of the inner membrane of mitochondrion?

Cristae

What divides mitochondrion into two internal compartments?

Inner membrane

What is the name for the space between the outer and inner membrane of the mitochondria?

Intermembrane space

What is the name for the fluid inside the the inner membrane of the mitochondria?

Mitochondrial matrix

What carries out photosynthesis?

Chloroplasts

How do chloroplasts carry out photosynthesis?

By converting light energy into chemical energy of sugars

What is the name of the disc-like sacs the inner membrane of chloroplasts is folded into?

Thylakoids

What do thylakoids contain?

Chlorophyll

What is chlorophyll?

The main light collecting pigment in plants

What is the name for a stack/stacks of thylakoids?

Granum/grana

What is the name for the interior of thylakoids?

Lumen

What is the name for the fluid surrounding the thylakoids?

Stroma

What is the endomembrane system?

Internal network of membrane-bound organelles found inside eukaryotic cells with similar membranes made of phospholipids

What does the endomembrane system do?

Facilitate cellular processes

How does the endomembrane system facilitate cellular processes?

By minimizing competing interactions and by increase surface area for chemical reactions

What does the endomembrane system include?

Cell membrane, nucleus, endoplasmic reticulum, golgi apparatus, lysosomes, vesicles, and vacuoles

What is the nucleus of the cell?

Double membranous structure that contains the cell's DNA

What does double membrane refer to?

Two lipid bilayers

What is DNA organized into within the nucleus of a eukaryotic cell?

Chromatin fiber

What are chromatin fibers?

DNA strands wrapped and organized around complex histone proteins

What is the membrane of the nucleus?

Nuclear envelope

What does the nuclear envelope of the nucleus contain?

Nuclear pores that allow materials to enter and exit the cell

What is the nucleolus?

Dense region in nucleus where ribosomal subunits are synthesized

What is the endoplasmic reticulum?

Interconnected network of membrane that is continuous with the nuclear envelope

What does the highly folded nature of the endoplasmic reticulum significantly increase?

The surface area inside the cell

What does the significantly increased surface area of the endoplasmic reticulum allow for?

The synthesis of many materials

What are the two types of the endoplasmic reticulum?

Rough (RER) and smooth (SER)

What is the rough endoplasmic reticulum (RER)?

Membrane covered in ribosomes

What is the smooth endoplasmic reticulum (SER)?

Membrane that lacks ribosomes but contains enzymes