Lecture 1

Question 1

How many cell types does the body contain?

Answer 1

200 different cel types

Question 2

What are the 3 major sub divisions of the cell ?

Answer 2

Plasma membrane
Nucleus
cytosol/plasm

Question 3

Plasma membrane function

Answer 3

Acts as a barrier

separates intracellular and extracellular fluid

Question 4

Plasma membrane structure

Answer 4

Lipid bilayer
Hydrophilic (polar) heads and lipophilic (nonpolar) tails

Many proteins that run completely/ partially through the membrane

Question 5

Nucleus

Answer 5

Largest single cellular component and contains the genetic material of the cell DNA

Question 6

Nuclear envelope

Answer 6

Surrounds the nucleus
= lipid bilayer

Contains any nuclear pores that allow for proteins, DNA & RNA to move between the cytosol and the nucleus

Question 7

Cytosol

Answer 7

Complex gel like liquid surrounding the organelles

Occupies 55% of the total cell volume

Question 8

Cytoplasm

Answer 8

Contains the membrane bound organs in the cytosol

Ie. Cytosol + organelles

Question 9

6 main types of organelles

Answer 9

Nucleus 
ER
Golgi 
Lysosomes 
Peroxisomes
Mitochondria 
Vaults*

Question 10

ER

Answer 10

Membrane system that is distributed throughout the cytoplasm

• mainly involved in protein and lipid synthesis

2 types : rough and smooth

Question 11

Rough ER

Answer 11

Outer surface has lots of ribosomes
- ie. Ribosomal RNA protein complexes involved in the synthesis of protein

• interact with mRNA

There are also free ribosomes in the cytosol

All proteins made here have a sorting signal

Question 12

What happens to proteins made in the ER?

Answer 12

After the ribosomes make the synthesized protein it is released into the ER lumen where it undoes folding and modifications

Then the folded protein is transported through the ER to the golgi

Question 13

Smooth ER

Answer 13

No ribosomes
Ie. Not involved in protein synthesis

Serves primarily as a final packaging and discharge site for molecules transported to the golgi

Question 14

Golgi

Answer 14

Stack of flattened, membrane- bound sacs called cisternae

Question 15

Functions of golgi

Answer 15

Processing the raw molecules from the ER into finished products [ie. Accessorizing -adding groups]

Sorting and directing these molecules to their final destination [organelles or plasma membrane] - note that different parts of the golgi have parts specific to the location that the product is going. Ie. The plasma membrane products located differently from nucleus products.

Question 16

Steps of protein transportation

Answer 16

1. Synthesis in the rough ER
2. Packaging and budding in the Smooth ER
3. Fusion with the golgi complex
4. Processing and sorting in golgi
5. Budding from golgi and transport to plasma membrane
6. Fusion with plasma membrane with exocytosis or membrane insertion

Question 17

Exocytosis

Answer 17

The secretory vesicle blinds and fuses with the membrane, which then leads it to release the material outside

Question 18

What proteins are involved in exocytosis?

Answer 18

NOTE: all proteins from the RER have a sorting signal - where in the golgi do i go to?

It involves the interaction of many proteins in the budding from the golgi complex such as [these are facing the cytosol):
Coat protein
Docking marker (v-snare)
Recognition marker

Then the fusion to the plasma membrane/ organelle involves :
Docking acceptor protein (t-snare)

Question 19

Lysosomes

Answer 19

Membrane bound organelles that sever as the intercellular digestive system
- contain hydrolytic enzymes that break down the organic compounds ingested by the cell via a process called endocytosis

• so the nutrients can be used to make other things inside the cell
• can also degrade something bad
• also get rid of old organelles

Question 20

Endocytosis types

Answer 20

1. Pinocytosis
2. Receptor-mediated endocytosis
3. Phagocytosis

Question 21

Pinocytosis

Answer 21

This is cell drinking

Non-selective uptake

Question 22

Receptor mediated endocytosis

Answer 22

Highly selective uptake

Triggered by a ligands binding to its receptor

Question 23

Phagocytosis

Answer 23

Internalization of large, multi molecular particles like bacteria or red blood cells

Question 24

peroxisomes

Answer 24

Membrane bound organelles that contain oxidative enzymes and most of the cell”s catalase

Question 25

Oxidation

Answer 25

Involved in the detoxification of various wastes produced in the cell and foreign toxins ingested by the cell - oxidation causes the production of peroxide which is toxic to the cell

Question 26

Mitochondria

Answer 26

Power plants of the cell as they supply the cell with 90% of its energy in the form of ATP Double membrane

Question 27

Membranes of mitochondria

Answer 27

Outer membrane: surrounds the organelle Inner membrane: forms a series of infoldings called cristae

Question 28

What does the mitochondria specifically do?

Answer 28

1. It uses pyruvic acid molecules from glycolysis 2. This is then taken up by the mitochondria and is converted to ATP via enzyme reactions in the matrix 3. Excess hydrogen in the form of NADH is also produced [NOTE: steps 2 and 3 called TCA] 4. Electron transport chain converts excess H+ into ATP via the movement of H+ across the inner mitochondrial membrane

Question 29

Glycolysis location

Answer 29

Enzymes are located in the cytosol

Question 30

Glycolysis function

Answer 30

Breaks down glucose into pyruvic acid

Question 31

What occurs in the cytosol?

Answer 31

1. Metabolic processes like glycolysis 2. Ribosomal protein synthesis 3. Storage of fat, carbs {glycogen}, and secretory vesicles

Question 32

Cytoskeleton

Answer 32

Intracellular scaffolding to give cell shape and structure - also intracellular highway for trafficking vesicles to and from the plasma membrane

Question 33

What makes up cytoskeleton?

Answer 33

1. Microfilaments [actin] 2. Microtubules [tubulin] 3. Intermediate filaments

Question 34

Homeostasis

Answer 34

Maintenance of a stable environment Essential for the survival of each cell and every cell contributes to the maintenance of the internal environment shared by the cells

Question 35

Vaults

Answer 35

Classified as organelles Don’t know exact functions yet

Question 36

Specialized cell

Answer 36

Can have a larger smooth ER | Ex. Liver, Skeletal, steroid hormone secreting cells

Question 37

Smooth ER in skeletal muscle

Answer 37

Called sarcoplasmic- reticulum function is to store lots of calcium

Question 38

Smooth ER in endocrine cells

Answer 38

Stores a lot of cholesterol

Question 39

Smooth ER in liver

Answer 39

Detoxifying enzymes

Question 40

Coat protein

Answer 40

cytosolic proteins Bind the coat protein acceptor signals on the outside of the golgi membrane When they bind, start to impart curvature to the outside of the golgi membrane and keep pulling until they get a full vesicle General term for them is COP

Question 41

Docking marker protein

Answer 41

How we get to the plasma membrane , outside of the secretory vesicles done budding The specific docking marker is called the v-SNARE V = Vesicle Vesicle will go to target [in image = plasma membrane] - coat falls off after it makes vesicle - green in image

Question 42

T- snare

Answer 42

V snare’s target is t-snare They bind together Reactions occur, which allows ca to enter vesicle. Ca then triggers fusion of the 2 membranes

Question 43

Catalase

Answer 43

2 H2o2 -> 2 H20 + O2 | Breaks down peroxide

Question 44

Glycolysis

Answer 44

Glycogen -> stored glucose Glucose -> pyurvic acid - 2 ATP

Question 45

Pyruvate

Answer 45

Kreb cycle - 2ATP | FADH and NADH - fuel oxphos

Question 46

OXphos

Answer 46

28 - 32 ATP from single glucose

Question 47

Total ATP generated from oxphos

Answer 47

32- 36

Question 48

Actin

Answer 48

2 strands helically wrap around eachother

Question 49

Microtubules

Answer 49

Hollow tube Highway for vesicles - ie. In neuron Kinesin - moves and carry vesicle out Dynein - to move in

Question 50

Intermediate filaments

Answer 50

Not made of a single protein | Middle in size

Question 51

Kinesin

Answer 51

Uses ATP | Exocytosis

Question 52

Dynein

Answer 52

Endocytosis Has to go to cell body Cleave ATP