Chapter 3- Cellular level of Organization pt.2 Flashcards

1
Q

Plasma membrane is SELECTIVELY PERMEABLE meaning

A

it allows some materials to move freely, and restricts other materials

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2
Q

Active transport

A

requires energy & ATP

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3
Q

Passive transport

A

no energy required

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4
Q

Diffusion (Passive)

-can be simple/channel-mediated

A

Always follows concentration gradient, moves “down” concent. from high to low concentration gradient which allows movement

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5
Q

Carrier-mediated transport (passive/active)

A

-of ions and organic substances

movement of molecules across cell membrane via special transport proteins that are embedded

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6
Q

Vesicular transport (active)

A

movement within a vesicle

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7
Q

5 factors that influence rate of diffusion in cells

A
  1. Distance particle has to move
    - effective across short distances
  2. Molecule size
    - smaller is faster
  3. Temperature
    - more heat, faster motion
  4. Concentration Gradient
    - larger gradient, faster diffusion
  5. Electrical Forces
    - opposites attract, likes forces repel
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8
Q

Intracellular

A

Potassium

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9
Q

Extracellular

A

Sodium & Calcium, Chloride

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10
Q

Why is there a bigger concentration of amino acids inside the cell than outside?

A

Because amino acids are the building blocks of all cells

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11
Q

Simple Diffusion

A

Materials diffuse directly through plasma membrane w/o use of protein channel.
EX: triglycerides, lipids, steroids, testosterone, estrogen, cholesterol

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12
Q

Lipid soluble molecules pass into a cell by what method?

A

Simple diffusion

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13
Q

Channel-mediated diffusion

A

A concentration gradient drives movement of solute through a transmembrane channel protein
EX: Leak channels for Na, K, or Cl

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14
Q

Channel-mediated diffusion (polar & ionic molecules)

A

A concentration gradient drives movement of solute through a transmembrane channel protein
EX: Leak channels for Na, K, or Cl

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15
Q

Osmolarity

A

measure of solute concentration

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16
Q

Isotonic

A

A solution that does not cause osmotic flow of water in/out of cell

17
Q

Hypotonic

A

Has less solutes and loses water through osmosis –>water flows into cell
-Ruptures (LYSING/HEMOLYSIS of red blood cells)

18
Q

Hypertonic

A

Has more solutes and gains water by osmosis –> water moves out of cell
-Shrinks (CRENATION of red blood cells)

19
Q

3 Characteristics common in carrier-mediated transport

A
  1. Specificity
    - one transport protein, one set of substrates
  2. Saturation limits
    - Rate depends on the speed and number of transport proteins, not substrate
  3. Regulation
    - cofactors such as hormones play an important role in coordinating carrier protein activity
20
Q

Carrier-Mediated Transport: FACILITATED DIFFUSION

A

Passive.
-Carrier proteins transport molecules too large to fit through channel proteins
EX: glucose, amino acids
*molecule binds to receptor site on carrier protein
*protein changes shape, molecules pass through
*receptor site is specific to certain molecules

21
Q

Carrier-Mediated Transport: ACTIVE TRANSPORT **Pump (primary or secondary)

A
  • moves substrates against concentration gradient, from an area of low concentration to high concentration
  • requires energy, such as ATP
22
Q

Carrier-Mediated Transport: ACTIVE TRANSPORT **Pump (primary or secondary)

A

-moves substrates against concentration gradient, from an area of low concentration to high concentration
*requires energy, such as ATP
ION PUMPS: move ions against concentration gradient
EXCHANGE PUMPS: exchange of molecules

23
Q

Primary Active Transport

A

Sodium-Potassium exchange pump:

*Sodium ions out, Potassium ions in

24
Q

Secondary Active Transport (another kind of facilitated diffusion)

A

Glucose and Sodium enter cell through facilitated diffusion. Another channel will pump Sodium out of cell.

25
Q

Vesicular transport (Bulk transport)

A

Materials move in and out of cell in vesicles

*Endo (inside) cytosis: active transport using ATP, enter the cell

26
Q

Endocytosis

A

-Pinocytosis:

27
Q

Endocytosis *requires ATP

A

-Pinocytosis: cells “drink” extracellular fluid

28
Q

Phagocytosis *requires ATP

A

Used by specialized cells such as macrophages to surround & engulf an object using pseudopods “cell eating”

29
Q

Exocytosis *requires ATP

A

Granules/droplets released from cell

EX: mucus, hormones, proteins

30
Q

The interior of a cell has a slightly _______ charge w/ respect to the outside. What causes this?

A

NEGATIVE

Resting potential –> negatively charged protein molecules inside cannot cross membrane

31
Q

Neurons can conduct electrical signals and muscles can contract, because they have a membrane potential. What is meant by the term RESTING MEMBRANE?

A

When a neuron is not sending a signal, it is “at rest”

32
Q

New cells are created in the body by a process of _____.

A

Mitosis

33
Q

5 steps in DNA REPLICATION

A

1.

34
Q

5 steps in DNA REPLICATION (S phase of Interphase)

A
  1. Enzymes called helicases unwind the strands & disrupt the weak hydrogen bonds btwn bases. Molecules of DNA polymerase bind to the exposed nitrogenous bases
  2. As the 2 original strands separate, DNA polymerase binds to them. DNA polymerase, bound to upper leading strand template adds nucleotides to make a single continuous complementary copy called the leading strand that grows toward “zipper”
  3. In the lower lagging strand template, the 1st DNA polymerase to bind to it must work from left to right, adding nucleotides in sequence 12345
  4. DNA ligases splice together the 2 DNA segments into a lagging strand
  5. Unzipping completely separates the original strands. 2 identical DNA molecules are formed. leaves interphase and proceeds to mitosis
35
Q

Phases of Interphase

A

Interphase: Non-diving period
G0- specialized cell functions only
G1- cell growth, organelle duplication, protein synthesis
S phase- DNA replication, and histone synthesis
G2- finishes protein synthesis & centriole replication

36
Q

5 steps of Mitosis

A
  1. Prophase
    - DNA condenses to chromosomes
    - centrioles move to the poles of the cell
    - nuclear envelope disintegrates
  2. Metaphase
    - Centrioles, using spindle fibers, pull chromosomes to the middle of the cell
  3. Anaphase
    - Centrioles pull chromosomes apart to opposite poles of the cell
  4. Telophase
    - Nuclear envelope reforms around chromosomes
37
Q

Cytokinesis

A

Divides cytoplasm and organelles into 2 daughter cells

38
Q

Stem Cell

A

Undifferentiated biological cells that can differentiate into specialized cell and can divide to produce more