Eukaryotes (Cell Structure- Organelles)

Question 1

cell theory

Answer 1

• All living things are made of cells
• cells represent smallest living thing
• cells come from previously existing cells

Question 2

plasma membrane

Answer 2

a phospholipid bilayer (with proteins, etc) with genetic material (DNA) in the middle

Question 3

Prokaryotes

Answer 3

• “Pro-” before the nucleus
• genetic material in the middle without another membrane surrounding the DNA
• *All bacteria are prokaryotes.

Question 4

Eukaryotes

Answer 4

real nucleus which contains DNA and has as a nuclear envelope or a membrane for the nucleus
*all other living things

Question 5

electron microscope

Answer 5

needed to look at substructure in cells
2 micrometers
.2 micrometers- can see ribosome
2nm- diameter of DNA strand
.1 nm - 1 angstrom, diameter of H atom

Question 6

bacterial cell

Answer 6

2.5 microns long, 10X smaller than eukaryotic
Plasma membrane surrounding some substance in the middle (cytoplasm, cyto- cell)
DNA inside

Question 7

Nucleoid region

Answer 7

• no membrane around it- where genetic material is found

- prokaryotic cells

Question 8

Cell wall

Answer 8

• just outside of the plasma membrane
• made of peptidoglycan in bacterial cells
• made of cellulose in plant cells

Question 9

Nucleus

Answer 9

• Membrane bound structure→ creates a separate chamber where genetic material is stored
• Membrane = nuclear envelope
• 2 membranes (double membrane) that create space called lumen
• ribosomes assembled in nucleus

Question 10

Organelles

Answer 10

small organs inside cells

Question 11

3 cifferences in plant cells

Answer 11

Cell wall
Chloroplast
Large central vacuole (animal cells often have small)

Question 12

Nuclear envelope

Answer 12

• Inner and outer layer of nuclear membrane
• pores- holes in membrane
• complex structure that allows things to move in and out
• ex. DNA gets shipped out and will go through pores

Question 13

lumen

Answer 13

• also called perinuclear space
• region between the two lipid bilayers of the nuclear envelope
• also in ER (ribosomes only on exterior of lumen)

Question 14

Nuclear pore complex

Answer 14

Pores are complex structures, not just holes

Regulate what goes in and what comes out

Question 15

Nucleolus

Answer 15

• within the nucleus
• area where ribosomes are being assembled
• rRNA is made here- used to make the ribosomal structures–> transcription
• Sometimes the nucleolus will go away depending on the stage of the cell

Question 16

Chromatin

Answer 16

• material in the nucleus that takes up a colored stain
• DNA in the nucleus + associated proteins and some RNA
• two types- Heterochromatin and Euchromatin

Question 17

Heterochromatin

Answer 17

• Condensed and inactive chromatin around the edges of the nucleus
• Light staining
• ex. liver genes would be “off” in a skin cell, so it would be in the heterochromatin

Question 18

Euchromatin

Answer 18

• Chromatin that is actively expressing genes
• in the middle of cell- to do work
• dark staining
• ex. liver genes would be “on” in liver cells, so in the euchromatin

Question 19

Genes

Answer 19

genetic material that is making particular proteins

expressed in the middle of the nucleus

Question 20

Lysosome

Answer 20

• Lysis- split, Some = body/structure
• membrane bound sac that contains dozens of enzymes that break down macromolecules into monomers that can be recycled
• pH optimum
• Phospholipid bilayer around it
  break down food from outside cell, and old organelles from inside cell

Question 21

pH optimum (lysosome)/proton pump (acid hydrolysis)

Answer 21

• Internal pH ~7.0, when activated, pH lowers to ~5.0
• Membrane has an ion channel (proton pump) that can pump in H+–> pH falls (becomes acidic), and the enzymes become active for digestive
• breaks down macromolecules into monomers by adding water
• Monomers are shipped out by metabolite transporter for use of other things

Question 22

Secretory pathway- Phagocytosis (lysosome)

Answer 22

• cell eats food from environment
• phagocytosis creates vesicle called an endosome = food vesicle
• vesicle fuses together with a lysosome
• goes into combined chamber of vesicles (2 prime) which is further digested
  Digestive enzymes in lysosome break down food particle
  Proton pump starts up and turn pH down

Question 23

primary/secondary lysosome

Answer 23

primary- lysosome is first produced

secondary0 when pH is lowered

Question 24

smooth endoplasmic reticulum

Answer 24

• No ribosomes here
• make carbohydrates and lipids
• Detoxifies material from outside of cell

Question 25

rough endoplasmic reticulum

Answer 25

• With ribosomes stuck to the membranes
• making proteins for export
• proteins secreted out of cell to be used in biological membranes

Question 26

Signal Hypothesis (Gunther Blobel)

Answer 26

• all protein synthesis starts in cytoplasm on free ribosomes
• if the signal is present, it moves to the rough ER, if the signal is not present, it will remain in the cytoplasm
• if chain has nonpolar properties- signal protein (SRP) will pull whole chain to membrane of ER and directs newly synthesizing proteins through pore to complete synthesis

Question 27

Golgi apparatus

Answer 27

• series of membranes that are stacked closely together
• Site of sorting, packaging, and shipping
• Assembly of compound proteins
• Polypeptide, attach sugars, fat→ called glycolipids, lipoproteins, glycoproteins
• Organizes enzymes for where they should go
• range of signals to tell where golgi to send something

Question 28

circular transport (golgi), secretory pathway

Answer 28

• Er Lumen comes off in little vesicles, fuses with golgi
• Proteins get sorted→ then some are secreted–> fuse with membrane
  CIS side- receiving
  TRANS side- sending

Question 29

BSA

Answer 29

Secretory pathway made on rough ER and goes through golgi- circulates through blood to keep osmotic balance

Question 30

Mitochondria

Answer 30

• Energy managing organelle, long and thin
• Mito- thread-like
• double membrane- creates intermembrane space
• Inner membrane is folded up = called crista–> creates large surface area
• Makes ATP

Question 31

Chloroplast

Answer 31

Energy managing organelle in plants

Question 32

Peroxisome in epithelial cell (glyoxysome in plants)

Answer 32

• organelle membrane bound compartment- has specialized enzymes that deal with reactive oxygen species
• to keep toxic intermediate products produced in biochemical reactions in chamber so they don’t interfere with other things
• Might produce a free oxygen radical
• Highly reactive, enzyme converts it to H2O2 (which is also a little reactive but not as reactive)–> enzyme detoxifies product

Question 33

epithelial cell (polarized)

Answer 33

• lines a void and creates barrier of tight junctions between lumen on one side and tissues underneath
• polarized cells- functional differences of top and bottom
• Microvilli at top of cell- “finger” like- job of absorbing good nutrients (sugars and amino acids), increases area of cell
• Bottom of cell- job is to secrete materials that are absorbed at the top, ship them out

Question 34

housekeeping gene

Answer 34

• active genes in all cells that do normal processes

Question 35

protein syntehsis

Answer 35

• synthesized in cytoplasm
• mRNA looks for signal
• signal present
• SRP takes protein to ER
• ER forms vesicle with protein
• sent to golgi
• packages/ships to new

Question 36

vacuole

Answer 36

• in animal and plant cells

- space filled with something (food, water)

Question 37

cytosol

Answer 37

• the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.