Chapter 2 - The Cytoplasm

Question 1

Differentiation

Answer 1

• cells become specialized from development from zygote to adult
• specialization of cell to produce proteins that carry out specific functions (genetically determined)
• EX: organelles, appearance, function

Question 2

Plasma membrane

Answer 2

• separates cytoplasm from the environment
• lipid bilayer
  controls transport in and out
  signaling

Question 3

Fluid mosaic model

Answer 3

• describes structure of plasma membrane
• phospholipids like cholesterol
• proteins
• glycolipids and glycoproteins

Question 4

What are the two types of proteins in the fluid mosaic model? How are the glycolipids and glycoproteins oriented?

Answer 4

• integral proteins - buried in membrane, have carb modifications for signaling
• peripheral - loosely associated/bound w/ inner surface of membrane
• carb portion of glycolipids and glycoproteins is always oriented externally

Question 5

Organelles

Answer 5

• membrane-bound compartments w/n a eukaryotic cell
• distinct functions = distinct enzymes and proteins
• may be different amounts of organelles per cell depending on function

Question 6

Mitochondria

Answer 6

• site of oxidative phosphorylation - cell consumes O2 and makes ATP
• rod shaped in most cells
• 2 membranes
• inner membrane highly folded, forming cristae
• inner matrix is the site of Kreb’s cycle, also contains ribosomes

Question 7

What is the site of e- transport chain in the mitochondria? Why is it formed the way it is?

Answer 7

• inner membrane
• give more surface area to hold more protein

Question 8

Give a brief explanation of the Krebs cycle, where does it occur?

Answer 8

• facilitates NADH interaction w/ e- transport chain
• intermembrane space - H+ pumped here by e- transport chain
• ribosomes encode some of the e- transport chain enzymes
• inner matrix of mitochondria

Question 9

Endosymbiotic theory

Answer 9

• mitochondria and chloroplasts were believed to derive from anaerobic cells due to their inner matrixes containing ribosomes that resemble bacterial ribosomes, and why their chromosomes resemble bacterial chromosomes

Question 10

Ribosomes

Answer 10

• translate mRNA to protein
• 2 subunits
• comprised of rRNA and proteins
• assembled in nucleus
• found in cytoplasm, RER, mitochondria, chloroplasts

Question 11

Where are rRNA and the subunits of the ribosomes transcribed?

Answer 11

nucleolus of ribosome

Question 12

Endoplasmic reticulum

Answer 12

• major site for protein synthesis
• continuous w/ outer layer of lipid bilayer

Question 13

Rough ER

Answer 13

• continuous w/ nuclear membrane
• ribosomes on surface, protein release into ER membrane of cisterna
• modifies proteins not destined for cytoplasm
• initial glycosylation or glycoproteins
• synthesis of phospholipids

Question 14

Smooth ER

Answer 14

• continuous w/ RER
• no ribosomes
• synthesis of steroids

Question 15

Macromolecular membrane transport

Answer 15

vesicles moving large portions of things

Question 16

Pinocytosis

Answer 16

• cell drinking, fluid/liquid intake via small vesicles

Question 17

Endocytosis

Answer 17

• cell bringing in a large particle or large amount of material from outside of cell

Question 18

Phagocytosis

Answer 18

• form of endocytosis
• neutrophil surrounds and engulfs a particles, pulls it inside of the cells, kills it and recycles the material

Question 19

Receptor-mediated endocytosis

Answer 19

• form of endocytosis
• bringing in a large amount of a specific molecule that bind to receptors on the cell surface
• cluster together to bind a large amount of things together, and then brings them into the cell

Question 20

Exocytosis

Answer 20

• reverse of pinocytosis
• vesicle brings molecules to cell surface, which are then excreted
• protein and fluid secretion, NT release