EUKARYOTIC CELLS

eukaryotic cells

• Membrane-bound nucleus that houses dna

• Specialized organelles

prokaryotes

what were the first cells ?

archaea

eukaryotes are most closely related to ____

Nucleus—> Endomembrane System—> Mitochondrion—>Chloroplast

how did the eukaryotic cell develop?

nucleus, endoplasmic reitculum, and golgi apparatus

the __________ is believed to have EVOLVED by the invagination of the plasma membrane. The invagination process also explains origins of ________ and _________.

mitochondria and chloroplasts

energy organelles like _________ and ____ may have originated when larger cells engulfed smaller prokaryotic cells

endosymbiotic theory

is the name of the hypotheses that eukaryotic cells would have benefited from the ability to utilize oxygen or synthesize organic food

endomembrane system

- Organelles that communicated with one another

1. Via membrane channels

2. Via small vesicles

how did the endomembrane system communicate?

energy-related organelles

• Mitochondria and chloroplasts

• Independent and self-sufficient

endomembrane system and energy related organelles

two classes of organelles

nucleus

Command center of cell,

nuclear envelope

Consists of a DOUBLE-LAYER membrane

nuclear pores

permits exchange between nucleoplasm and cytoplasm

chromatin

contains nucleic acids and proteins

dark nucleolus

composed of rRNA

ribosomes

• Composed of rRNA

Consist of a large subunit and a small subunit

nuecleolus

subunits are made in the ____

endoplasmic reticulum and cytoplasm

ribosomes may be located in the _____ and ____

polyribosomes

ribosomes can be located in the cytoplasm in singly or groups called ____

ribosomes

• Site of protein synthesis in the cell

• In the process of transcription and translation:

endomembrane system

Series of intercellular membranes that compartmentalize the cell.

endoplasmic reticulum, nuclear envelope, golgi apparatus, and vesicles

parts of the endomembrane system

endoplasmic reticulum

 A system of membrane channels and saccules ( flattened vesicles) continuous with the outer membrane of the nuclear envelope

saccules

flattened vesicles

rough er

• Studded with ribosomes on cytoplasmic side 

• Has the capacity to produce proteins 

• Modifies and processes proteins 

1. Adds sugar to protein

2. Results in glyco proteins 

I. important in cell functions

smooth er

• No ribosomes 

• Synthesis of lipids

1. In tests, testosterone is produced by smooth ER

• Site of various synthetic processes, detoxification, and storage

1. The liver, with abundant smooth ER, detoxifies drugs

golgi apparatus

Consists of flattened, curved saccules

. 

Modifies proteins and lipids with “signal” sequences 

Receives vesicles from ER on cis (or inner) face 

After modification, prepare for “shipment” and packages proteins and lipids in vesicles that leave Golgi from the trans (or outer) face. 

exocytosis

exported from the cell

vesicles

production of specific molecules takes place in or on organelles by enzymes in membranes

vesicles

Products are transported around the cell by _____

sacs made of membranes

vesicles are ________________

cytoskeletal network

vesicles move around using the _____

lysosomes

• membrane-bound vesicles (not found in plants)

• produced by the golgi apparatus 

• contain powerful hydrolytic digestive enzymes and are highly acidic 

  1. digests large molecules into simpler subunits 

  2. recycle cellular resources 

3. in white blood cells, they engulf pathogens

microbodies

contain specialized enzymes to perform special metabolic functions

vacuoles

• membranous sacs that are larger than vesicles 

• store materials that occur in excess

• others are very specialized

central vacuole

accounts for 90% of the volume in some cells in plants

vacuole

storage of water, nutrients, pigments, and waste products

vacuole

• development of turgor pressure 

• toxic substances used for protection from herbivores 

• some functions performed by lysosomes in other eukaryote

chloroplast

• bounded by double membrane 

serve as sites of photosynthesis

thylakoids

disc like things in the chlorplast

grana

stacked thylakoids

stroma

chloroplast suspended in semi fluid

mitochondria

• smaller than chloroplast 

• numbers vary with metabolic activities and energy requirements of cells 

matrix

inner membrane surrounds ____ in mitochondria

matrix

inner semifluid substance containing respiratory enzymes

cristae

matrix convoluted (folded) to form ____

cytoskeleton

•  maintains cell shape (similar to the bones and muscles of an animal) 

• assists in movement of cell and organelles 

• makes internal transport possible

actin filament

intercellular traffic control, muscle contraction, animal cell division

intermediate filament

support nuclear envelope, cell-cell junctions

microtubules

distributes chromosomes during cell division

centrioles

• short, hollow cylinders 

• one pair per animal cell

• located in centrosome only

27 microtubules, nine overlapping triplets

centrioles are composed of ____ microtubules arranged into ____ overlapping ____

Cilia and Flagella

hairlike projections from the cell surface that aid in eukaryotic cell movement

flagella

• outer covering of plasma membrane

• inside this is a cylinder of 18 microtubules arranged in 9 pairs 

• in the center are two single microtubules 

false; cilia are much SHORTER than flagella

T OR F: in eukaryotes, cilia are much longer than flagella

cilia

move in coordinated waves like oars

flgaella

move like a propeller or corkscrew

plasma membrane

• separates internal cytoplasm from the external environment of the cell

• allows sometimes incompatible chemical reactions to occurs simultaneously 

phospholipid bilayer

• external surface lined with hydrophilic polar heads 

• cytoplasmic surface lined with hydrophilic polar heads. 

• non polar hydrophobic, fatty acids tails sandwiched in between

periphreal protein

are found on the inner membrane surface (protein)

integral protein

are partial or wholly embedded (trans membranes) in the membrane (protein)

carbohydrate chains

• contribute to cell’s fingerprint

• important in tissue transplantation and blood transfusions

glycorpoteins

• proteins with attached carbohydrate chains 

glycolipids

lipids with attached carbohydrate chains

channel protein

KIND OF PROTEIN: allows a particular molecule or ion to cross the plasma membrane freely. 

carrier protein

KIND OF PROTEIN: selectively interacts with a specific molecule or ion so that i can cross the plasma membrane. Glucose transporters move glucose in and out of the various celll types in the body. 

• the inability of some persons to use energy for sodium potassium transport has been suggested as the cause of their obesity

cell recognition protein / glycoprotein

KIND OF PROTEIN:the MHC (major histocompatibility. complex) glycoproteins are different for each person, so organ transplants are difficult to achieve. Cells with foreign MHC glycoproteins are attacked by white blood cells responsible for immunity. 

receptor protein

KIND OF PROTEIN:Is shaped in such a way that a specific molecule can bind to it. Some forms of dwarfism result not because the body does not produce enough growth hormone, but because their plasma membrane growth hormone receptors are faulty and cannot interact with growth hormone 

enzymatic protein

KIND OF PROTEIN:Catalyzes a specific reaction. The membrane protein adenylate cyclase, is involved in ATP metabolism. Cholera bacteria release a toxin that interferes with the proper functioning of adenylate cyclase; sodium (Na+) and water leave intestinal cells and the individual may die from severe diarrhea 

junction proteins

KIND OF PROTEIN:Tight junctions join cells so that a tissue can fulfill a function, as when a tissue pinches off the neural tube during development. Without this cooperation between cells, an animal embryo would have no nervous system

true

T OR F: plasma membrane is selectively permeable

concentration gradient

• Move from an area where they are in high concentration to an area of low concentration 

aquaporins

speed up water transport across membrane

carrier proteins

The movement of ions and polar molecules across the membrane is often assisted by which kind of proteins

Exocytosis

• fusion of a vesicle with the plasma membrane moves a particle outside the membrane 

Active transport

Some molecules must move against their concentration gradient with the expenditure of energy

Endocytosis

 vesicle formation moves particle to inside the plasma membrane

diffusion

is the net movement of molecules down a concentration gradient. Molecules move both ways along the gradient, but net movement is from high to low concentration.

Temperature, pressure, electrical currents, and molecular size

what are the 4 things that affect the rate of diffusion.

osmosis

• Special case of diffusion 

• Focuses on solvent movement rather than solute 

• Diffusion of water across a SELECTIVELY PERMEABLE MEMBRANE

osmotic pressure

is the pressure that develops due to osmosis.

 Isotonic Solutions 

• Solute and water concentrations are equal on both sides of cellular membrane 

• There is no net gain or loss of water by the cell

hypotonic

• Concentration of solute in the solution is lower than inside the cell. 

• Cells placed in hypotonic solution will swell 

  • Cause turgor pressure in plants 

  • May cause animal cells to lyse (rupture) 

hypertonic solution

• Concentration of solute is higher in the solution than inside the cell

• Cells placed in a hypertonic solution will shrink 

• Crenation in animal cells 

  • Example: red blood cells placed in a hypertonic solution 

• Plasmolysis in plant cells

bulk trasnport

Macromolecules are transported in or out of the cell inside vesicles

Endocytosis

cells engulf substances into a pouch which becomes a vesicle

Exocytosis

vesicles fuse with plasma membrane and SECRETE contents

phagocytois

large, solid material is taken in by endocytosis

• example : human white blood cells can engulf debris or viruses

pinocytosis

vesicles from around a liquid or very small particles (cell drinking)

Receptor-Mediated Endocytosis

specific form of pinocytosis using receptor proteins and a coated pit.