Exam 2

Question 1

What is a cell?

Answer 1

Fundamental units of life

Question 2

4 components of the cell

Answer 2

1. Plasma membrane
2. Cytoplasm
3. DNA
4. Ribosomes

Question 3

Prokaryotic

Answer 3

bacteria and archea (pre-nucleic cell/ mostly single celled)

Question 4

Eukaryotic examples

Answer 4

Plants, fungi, protist and animals

Question 5

Where is chromosomal DNA located?

Answer 5

In a nucleoid

Question 6

Why do we have more prokaryotic cells?

Answer 6

Because they are simpler and more tolerable to change, while if eukaryotic cells go through a change they die off.

Question 7

Why are prokaryotic cells so small?

Answer 7

Having the small surface area:volume ratio is more favorable for moving material in an out of the cell.

Question 8

Glyco-

Answer 8

Contains sugar

Question 9

DNA integrity:cannot change integrity

Answer 9

When copied the DNA doesn’t change

Question 10

Which type of cells require a lot of energy?

Answer 10

Eukaryotic cells

Question 11

Describe form/function of an organelle

Answer 11

It has an enclosed membrane in order to create a specific (and different) interior organelle

Question 12

Where is the cytoplasm?

Answer 12

The region between the plasma membrane and the nuclear envelope

Question 13

What is the nucleus?

Answer 13

The largest organelle (10% of cellular contents); bigger itself than most prokaryotic cells.

Question 14

What makes up the nucleus? remember fractions

Answer 14

2/3 chromatin (protein); 1/3 DNA

Question 15

What is the nuclear envelope and what does it do?

Answer 15

A double membrane structure and forms the outermost portion of the nucleus

Question 16

Where is the nucleolus?

Answer 16

The region inside the nucleus (where ribosomes are formed from RNA and proteins)

Question 17

What are the cellular structures responsible for protein synthesis (translation)?

Answer 17

Ribosomes

Question 18

What is the mitochondria?

Answer 18

An organelle that converts chemical energy to cellular energy

Question 19

What is a peroxisome and what does it do?

Answer 19

A small rounded organelles by a single membrane and it breaks down fatty acids

Question 20

What makes up centrosomes?

Answer 20

Consists of two centrioles that lie right next to each other

Question 21

What do lysosomes do?

Answer 21

Break down large biomolecules and even worn-out organelles. The “garbage disposal” and important to photosyntehsis.

Question 22

What are plant cell walls made up of?

Answer 22

Prokaryotes which are made up of cellulose (has a rigid protective structure).

Question 23

What do chloroplasts do?

Answer 23

Gives plants their color

Question 24

Compare/Contrast Animal and Plant cells.

Answer 24

Similarities: cell membrane, nucleus, mitochondria, ribosomes, and smooth/rough endoplasmic reticulum.

Differences: Animal cells have centrosomes, lysosomes, and flagellum. Plant cells have a cell wall, chloroplasts, and a central vacuole.

Question 25

What is the central vacuole?

Answer 25

‘Hypertonic’ referring to the amount of molecules inside the cell. It takes up the most space in plant cells.

Question 26

What membranes make up the endomembrane system?

Answer 26

-nuclear envelope -endoplasmic reticulum -golgi apparatus -lysosomes -vesicles

Question 27

What is one of the main functions of the smooth endoplasmic reticulum?

Answer 27

To de-toxicify our body

Question 28

Sarco-

Answer 28

Muscle cells

Question 29

What produces DNA?

Answer 29

Rough endoplasmic reticulum

Question 30

What are the microtubules made up of?

Answer 30

Tubulin dimers: 13 chains of dimers surround central cavity of microtubule.

Question 31

What do microfilaments do?

Answer 31

Determine/stabilize shape. Involved in movement (whole cell or internal parts). Made from actin monomers.

Question 32

What do intermediate filaments do?

Answer 32

Anchors organelle like the nucleus, mitochondria and chloroplasts in place.

Question 33

What do the cilia and flagella do?

Answer 33

Facilitate cellular movement. Cilia is shorter and more numerous.

Question 34

Describe the extracellular structures in plants (plant cell wall).

Answer 34

Support, barrier to infection, plasmodesmata.

Question 35

What are the 3 components of the extracellular matrix in animals?

Answer 35

-collagens/other fibrous proteins -glycoproteins called proteoglycans -linking proteins

Question 36

What do intercellular junctions do?

Answer 36

Provide direct channels of communication between cells

Question 37

What do tight junctions do?

Answer 37

Makes water tight seals between animal cells that prevent materials from leaking between cells (found in epithelial cells).

Question 38

What are desmosomes?

Answer 38

Short proteins in the plasma membrane (cadherins) **ONLY PRESENT IN ANIMALS**

Question 39

What do Gap Junctions do?

Answer 39

Connect animal cells, similar to plasmodesmata (set of six proteins).

Question 40

What are 3 functions of the plasma membrane?

Answer 40

1. Defines outer border of all cells and organelle 2. Maintain fluidity 3. Receiving external signals and initiating cellular responses

Question 41

The phospholipid bilayer…

Answer 41

Arranges themselves in a bilayer when in an aqueous environment (Structure: polar heads face outward and hydrophobic tails face inward).

Question 42

What is the second major component of membranes?

Answer 42

Proteins

Question 43

What is the third major component of membranes?

Answer 43

Carbohydrates (oligosaccharide carbohydrates): located on the exterior surface of the plasma membrane.

Question 44

Receptor Proteins

Answer 44

Our immune system’s T cells have CD4 receptor glycoproteins that recognize HIV as “self”

Question 45

Describe unsaturated fatty acids

Answer 45

-some double bonds between the carbons that kink the tials -packed loosely

Question 46

Describe saturated fatty acids

Answer 46

Filled with proteins because of single bonds

Question 47

How is membrane fluidity maintained?

Answer 47

It’s maintained in changing environments with the levels of saturation and cholesterol

Question 48

What is one of the main functions of the plasma membrane?

Answer 48

Transport; acts as a gatekeeper to molecules coming in and leaving

Question 49

What does selectively permeable mean?

Answer 49

The plasma membrane is very picky about what goes in and out. This is because it needs a very particular environment.

Question 50

What are the two types of transport?

Answer 50

Passive: requires no energy (molecules moves on its own). Active: requires ATP energy (molecules doesn’t want to move on its own)

Question 51

What are the 8 factors that affect Diffusion rate?

Answer 51

1.Concentration gradients 2. Mass of the molecules 3. Temperature 4. Solvent Density 5. Solubility 6. Surface area and membrane 7. Distance travelled 8. Pressure

Question 52

What are the two types of facilitated transport proteins?

Answer 52

1. Channel: lots of different ones depending on what that cell needs to do 2. Carrier: changes shape when bound to molecule in order to transport.

Question 53

What is osmosis?

Answer 53

The diffusion of water across a semipermeable membrane

Question 54

What does the TONICITY of a cell describe?

Answer 54

How full the cell is

Question 55

Hypertonic

Answer 55

Shriveled; H2O leaving the cell

Question 56

Isotonic

Answer 56

Normal; H2O leaving and entering the cell

Question 57

Hypotonic

Answer 57

Lysed; H2O enters cell

Question 58

Active Transport

Answer 58

ATP energy needed; moles work against the concentration gradient

Question 59

Electronica Gradient

Answer 59

Creates a difference between inside and outside charges of the cell

Question 60

What are the 3 types of carrier proteins?

Answer 60

1. Uniporter 2. Symporter 3. Antiporter

Question 61

What type of transport is antiporter?

Answer 61

Primary active transport

Question 62

What type of transport is symporter?

Answer 62

Secondary active transport

Question 63

Endocytosis

Answer 63

Importing by bulk transports

Question 64

Exocytosis

Answer 64

Exporting by bulk transport

Question 65

What are 3 types of endocytosis?

Answer 65

1. Phagocytosis 2. Pinocytosis 3. Receptor mediated endocytosis

Question 66

Phagocytosis

Answer 66

Cellular eating

Question 67

Pinocytosis

Answer 67

Drinks cells because water is being brought in

Question 68

Receptor-mediated endocytosis

Answer 68

Can choose what is eats and drinks; specificity

Question 69

What is the motive for passive transport?

Answer 69

Concentration

Question 70

What is filled with proteins because of single bonds?

Answer 70

Saturated lipids

Question 71

What contains less hydrogen because of double bonds?

Answer 71

Unsaturated lipids

Question 72

What are 4 components of the plasma membrane?

Answer 72

1. Phospholipids 2. Carbohydrates 3. Proteins 4. Chloesterol