Midterm 1: Eukaryotic Cells

Question 1

What is the cell membrane composed of (the fluid arrangement)?

Answer 1

Fluid Mosaic Model- Phospholipids, cholesterol, carbohydrates, and proteins (PCCP)

Question 2

Controls what enters and exits the cell.

Answer 2

Selective Permeable

Question 3

What easily enters the cell membrane WITHOUT help?

Answer 3

Fat-soluble, small, uncharged molecules

Question 4

What needs facilitated diffusion/help to move across the cell membrane?

Answer 4

Large, uncharged, water-soluble molecules and charged molecules

Question 5

What type of molecule is cholesterol?

Answer 5

Amphipathic (both hydrophobic and hydrophillic)

Question 6

Name the two functions of cholesterol in the cell membrane.

Answer 6

Reduce cell membrane: fluidity and permeability

Question 7

Name two different types of proteins:

Answer 7

Integral (intrinsic) and Peripheral (extrinsic)

Question 8

What are integral proteins?

Answer 8

have at least one HYDROPHOBIC region that anchors them to the hydrophobic core of the lipid bilayer

Question 9

What are Peripheral proteins?

Answer 9

Associate with one surface of the cell membrane, attached to integral proteins OR the hydrophillic head

Question 10

What are Transmembrane proteins?

Answer 10

Integral proteins that span the entire width of the membrane

Question 11

Name the 6 functions of the cell membrane.

Answer 11

JETRAT:
Junctions
Enzymes
Transport
Recognition
Anchorage
Transduction

Question 12

Where are carbohydrates located?

Answer 12

attached to proteins (glycoproteins) and fats (glycolipids)

Question 13

What are the 3 functions of carbohydrates?

Answer 13

Cushioning and protections for the cell membrane

JR: Junction and Recognition

Question 14

What is the Nucleus?

Answer 14

Storage facility for genetic information (DNA)

Question 15

Describe the process of DNA synthesis.

Answer 15

DNA–> mRNA (transcription)

mRNA–> protein (translation)

Question 16

Where does transcription occur?

Answer 16

nucleus

Question 17

Where does translation occur?

Answer 17

Ribosomes

Question 18

Describe the two layers of the nucleus’s lipid bilayer.

Answer 18

inner lipid bilayer: nuclear lamina

outer lipid bilayer: continuous with the ER

Question 19

What is the role of nuclear lamina?

Answer 19

inner lipid bilayer of the nucleus that is lined with protein and organizes DNA

Question 20

What are the holes perforating the nuclear envelope called?

Answer 20

Nuclear pores–lined with protein

Question 21

What is the role of nuclear pores?

Answer 21

they are lined with proteins that control what enter and exit the nucleus

Question 22

What is the semimatrix fluid that is found inside the nucleus called?

Answer 22

nucleoplasm

Question 23

What is found within nucleoplasm?

Answer 23

Chromatin and the Nucleolus

Question 24

What is chromatin?

Answer 24

DNA and protein

Question 25

What occurs within the nucleolus?

Answer 25

protein synthesis and rRNA synthesis

Question 26

Where is cytoplasm located?

Answer 26

between the cell membrane and the nucleus

Question 27

What 3 things are contained within the cytoplasm?

Answer 27

cytosol, cytoskeleton, and organelles

Question 28

What occurs in cytosol?

Answer 28

metabolic pathways: Glycolosis, glucogenesis, pentose phosphate pathway (PPP), and fatty acid synthesis

Question 29

What is contained within cytoskeleton?

Answer 29

fibrous proteins: actin, microtubles, and intermediate filaments

Question 30

What is the role of cytosol?

Answer 30

aqueous gel-like component of the cytoplasm where organelles (ions, small molecules, and macromolecules) are suspended

Question 31

What is the role of cytoskeleton?

Answer 31

Structure and support inside the cell: - anchors the cell - aids in cell motility - helps materials inside the cell move

Question 32

What are ribosomes composed of?

Answer 32

proteins and rRNA

Question 33

Where are ribosomes synthesized?

Answer 33

nucleolus

Question 34

What is the site of protein synthesis? (translation)

Answer 34

ribosomes

Question 35

Where are they found?

Answer 35

free (in cytosol) or bound (attached to ROUGH ER)

Question 36

What is the ER made of?

Answer 36

Lipid bilayer membrane--tubules and cisternae (flattened sacs) [lumen/cisternal space within tubules and sacs are fluid filled]

Question 37

What is the Smooth ER responsible for?

Answer 37

LIPID processing converts fat soluble toxins into h2o soluble substances sequesters Ca2+ from cytosol

Question 38

What is the Rough ER responsible for?

Answer 38

PROTEIN processing | transports proteins to Golgi bodies

Question 39

What are Golgi apparatus made of?

Answer 39

cisternae; membrane is lipid bilayer

Question 40

What is the Golgi's job?

Answer 40

modify proteins received by the rough ER

Question 41

What is the difference between Cis and Trans of Golgi?

Answer 41

Cis- receiving side | Trans- shipping side

Question 42

Mitochondria are composed of what 3 things?

Answer 42

circular DNA double membrane mitochondrial matrix

Question 43

What is the double membrane?

Answer 43

inner lipid bilayer--contains cristae (the deep folds) | outer lipid bilayer--define's organelles surface

Question 44

What is the mitochondrial matrix?

Answer 44

fluid-filled space in the inner membrane

Question 45

What is circular DNA?

Answer 45

can synthesize rRNA, tRNA, mRNA

Question 46

What metabolic activities occur in mitochondria?

Answer 46

Krebs cycle/ETC | Fatty acid oxidation

Question 47

What other role does mitochondria play?

Answer 47

apoptosis- programmed cell death

Question 48

What are lysosomes?

Answer 48

surrounded by a lipid membrane | site of intracellular digestion

Question 49

Approx. PH of lysosomes?

Answer 49

5

Question 50

What reactions are peroxisomes involved in?

Answer 50

fatty acid oxidation neutralize free radicals myelin synthesis cholesterol synthesis

Question 51

What is the extracellular matrix (ECM)?

Answer 51

3D network of macromolecules-- OUTSIDE the cell

Question 52

What is the most significant enzyme in the ECM?

Answer 52

matrix metalloproteinases

Question 53

What are the 2 classes of macromolecules in the ECM?

Answer 53

fibrous proteins | glycosaminoglycans (GAGs)

Question 54

Name the components of fibrous proteins?

Answer 54

structural (collagen and elastin) | adhesive (fibronectin and laminin)

Question 55

What are glycosaminoglycans (GAGs)?

Answer 55

unbranched polysaccharide chain composed of repeating disaccharide units--> most are linked to a specific core protein, forming proteogycans

Question 56

What fills the space of the EMC in the form of a hydrated gel?

Answer 56

GAGs

Question 57

What happens to the components of macromolecules?

Answer 57

they are synthesized intracellulary and then transported extracellulary via Exocytosis

Question 58

What are the 4 functions of the ECM?

Answer 58

Cell structure and support Anchor the cell in place cell binding--forming tissues regulates cellular functions (adhesion, growth, migration, differentiation)

Question 59

What are Proteins?

Answer 59

Large, complex molecules that do MOST of the work within the cell