Review for Exam 2 Flashcards

1
Q

when did simple bacteria evolve?

A

4 billion years ago

chemotrophic - survived on chemicals

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2
Q

when did photosynthetic cyanobacteria start to appear on earth?

A

2.5 billion years ago

autotrophic - made own food/released O2

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3
Q

ribozyme

A

RNA with catalytic activity

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4
Q

light microscope

A
  • observe live specimens

- natural colors or with stains

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5
Q

transmission electron microscope (TEM)

A
  • used to study internal ultrastructures & cross sections of cells/structures
  • electron beams aimed at thin section of a specimen
  • has been stained with metal to absorb electrons (enhances contrast)
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6
Q

scanning electron microscope (SEM)

A
  • used to view the surface features & 3-D shape of ultrastructures
  • specimen is coated with gold
  • electron beams scan surface, which excites the secondary electrons on the sample surface
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7
Q

cell fractionation

A

centrifugation is used to disrupt cells

  1. harvest tissues either fresh or been frozen (-700C / liquid N2)
  2. grind cells in buffer or N2. Keeps enzymes inactive
  3. homogenize cells in a buffer
  4. centrifuge a various speeds & durations to isolate components
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8
Q

gel electrophoresis

A
  • franctionates DNA, RNA, or protein molecules based on size
  • negative charge of DNA & RNA make them migrate towards the (+) anode thru tiny pores in gel
  • migrate depending on size & electric voltage of system
  • larger ones move slowly; smaller ones move fast
  • if voltage is increased, they move faster
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9
Q

polyacrylamide gels

A
  • used to fractionate proteins & DNA sequencing reactions
  • in gel electrophoresis
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10
Q

agarose gel electrophoresis

A
  • used to fractionate DNA or RNA
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11
Q

tight junctions

A

animal cell
2 cells are fused together
- prevents anything from passing
- epithelial cells in stomach

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12
Q

gap junctions

A

animal cell

  • connections between 2 cells thru connexons
  • chemical signals or solutes can pass from one cell to another
  • ex. heart muscle cells use to communicate
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13
Q

desmosomes (aka anchoring junction)

A

animal cell
aka anchoring junction
- spots where cells are connected by keratin-like fibrous proteins
- not as tightly sealed at tight junctions (some space between 2 cells)

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14
Q

cell junctions between plant cells

A

middle lamella

plasmodesmata

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15
Q

what layers does something need to get through to get inside a plant cell?

A

middle lamella (between cells)
primary cell wall
secondary cell wall
plasma membrane

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16
Q

what layers does something need to get through to get inside an animal cell?

A

plasma membrane

  • proteins
  • phospholipids
  • glycolipids
  • glycoproteins
  • sterol
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17
Q

what layers does something need to get through to get inside an plant cell?

A

middle lamella (between cells)
primary cell wall
secondary cell wall
plasma membrane

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18
Q

Function of: phospholipids

A

structure and fluidity

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19
Q

Function of: anchored proteins

A

structure

enzyme

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20
Q

Function of: transmembrane proteins

A

structure
transport
receptor
enzyme

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21
Q

Function of: oligosaccharides

A

AKA glycoprotein

cell to cell recognition

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22
Q

Function of: sterol / cholesterol

A

fluidity

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23
Q

Function of: peripheral proteins

A

structural

enzymatic

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24
Q

types of cellular communication

A
  1. intracellular - e.g. between cytoplasm & other organelles
  2. intercellular
    - gap junctions
    - paracrine - close by cells (cells release something that targets local cells)
    - endocrine - far away cells (travels thru bloodstream)stag
    - synaptic - nerve cells
  3. between organisms - uni- or multi-cellular
25
Q

stages of cellular communication

A
  1. signal reception
  2. transduction
  3. response
26
Q

ligand

A

a molecule that specifically binds to another molecule, often a larger one

27
Q

what happens during a cell signal pathway?

A

1st messenger signals a protein on the membrane (usually a G-protein coupled receptor)
This activates a specific protein (G-protein)
Which activates an enzyme (adenylyl cyclase)
Which catalyzes conversion of ATP to cAMP
– cAMP acts as 2nd messenger
– in turn, activates more proteins
Ultimately, causes a cellular response

28
Q

Name small, polar groups

How do they get through membrane?

A
  1. H2O
  2. Na+
    facilitated diffusion
    active transport
29
Q

Name small, non-polar groups

How do they get through membrane?

A

CO2
O2
CH4
simple diffusion

30
Q

medium polar groups

How do they get through membrane?

A

amino acid
glucose
sucrose
charged ions (Na+, Cl-)

facilitated diffusion
active transport

31
Q

medium non-polar groups

How do they get through membrane?

A

steroid
lipid soluble vitamins

simple diffusion

32
Q

ion channels

A

transport proteins imbedded in the cell membrane that facilitate the transport of charged ions & molecules across the membrane

33
Q

uniport

A

single solute
one direction
e.g. H+ pump

34
Q

symport

A

two solutes
moving in one direction (same)
e.g. sucrose/H+ pump

35
Q

antiport

A

two solutes
moving in opposite directions
e.g. Na+/K+ pump

36
Q

large polar groups

How do they get through membrane?

A

protein
DNA
RNA

exocytosis - leaving cell
endocytosis - bring into cell

37
Q

large non-polar groups

How do they get through the membrane?

A

fat globules
LDL
HDL cholesterol

exocytosis
endocytosis

38
Q

exocytosis

A

the organelle that contains something that needs to leave the cell fuses with the plasma membrane and opens outside to secrete the material

39
Q

endocytosis

A

phagocytosis - macrophage engulfing bacteria ID for destruction

pinocytosis - taking in liquids

receptor mediated endocytosis - specific receptor proteins recognize large molecules (cholesterol), change conformation & engulf LDL for cell processing

40
Q

Smooth ER

A

No ribosomes attached
Synthesizes lipids
Participates in carbohydrate metabolism
Detoxifies unwanted chemicals including drugs
Stores Ca2+ necessary for muscle contraction

41
Q

Rough ER

A

Ribosomes attached for membrane protein synthesis

- synthesizes membrane-bound proteins for secretion

42
Q

Golgi apparatus

A

Central receiving & dispatching center (proteins made in ER are sorted & packaged into vesicles & shipped to target sites

43
Q

Lysosomes

A

Membrane bags with hydrolytic enzymes (that come from Golgi or ER)
Acidic pH 5.0
Digest food
Excretes digested material into if wanted or outside cell if not

44
Q

Peroxisomes

A

Both plant and animal
Responsible for lipid degradation
Detoxification of active oxygen species
Contain enzymes - peroxidase & catalase

45
Q

Glyoxysomes

A

Plants only
Specialized Peroxisomes
Facilitate breakdown of storage lipids in germinating seeds

46
Q

Large central vacuole:

A

Found only in plants

Stores organic compounds, waste products, lytic enzymes, pigments and water

47
Q

Contractile vacuole

A

in fresh water protists

help remove excess water from cell

48
Q

energy organelles

A
  • mitochodria - impt for utilization of carbohydrates

- chloroplasts - imp for generation of carbohydrates

49
Q

Similarities between mitochondrion & chloroplasts

A
  • double membrane structure
  • have their own DNA & proteins
  • replicate autonomously
  • make ATP
  • import some proteins from cytoplasm
  • used for evolutionary studies
50
Q

Differences between mitochondrion & chloroplasts

A

mitochondrion - found in all higher eukaryotes
- perform respiration

chloroplasts - found in plants only
- perform photosynthesis & amino acid biosynthesis

51
Q

Endosymbiotic theory

A
  • proposed to explain how eukaryotic cells acquired chloroplasts & mitochondria
  • theory is that early primitive eukaryotes engulfed bacteria & other prokaryotes that had energy generating functions
52
Q

parts of mitochondrion & chloroplasts that correspond

A
  1. inner membrane - same
  2. cristae (m) – thylakoid (c)
  3. outer membrane - same
  4. matrix (m) – stroma (c)
  5. inner membrane - same
53
Q

parts that are unique to plant cells

A
  1. central vacuoles
  2. cell wall
  3. chloroplasts
  4. plasmodesmata
54
Q

parts that are unique to animal cells

A
  1. lysosomes
  2. centrosomes (w. centrioles)
  3. flagella
55
Q

plastids

A

plant organelles
make & store needed compounds
chloroplast is one

56
Q

what are the 3 major types of cytoskeleton elements?

A
  1. microtubules
  2. microfilament
  3. intermediate filaments
57
Q

microtubules

A

hollow tubes
made of alpha & beta tubulin (monomer)
Help in:
1. cell motility (flagella, cilia)
2. cell shape
3. chromosome movement
4. serve as tracks for movement of organelles

58
Q

mircofilaments

A
small filamentous
actin filaments (in all eukaryotes); myosin only in animal cells
Help in:
1.  amoeboidal movement
2.  muscle contraction 
3.  cytoplasmic streaming
4.  cleavage furrow during cell division
59
Q

intermediate filaments

A
hollow tubes made of keratin-like
almost all eukaryotic cells
Help in:
1.  structural support
2.  tensile strength
3.  cell shape
4.  anchoring nucleus & other cell organelles
5.  formation of nuclear lamina