Chapter 5- The Working Cell Flashcards Preview

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Flashcards in Chapter 5- The Working Cell Deck (71):
1

Nanotechnology

The manipulation of materials at the molecular scale.

2

Energy

The capacity to cause change

3

Kinetic energy

Energy of motion- muscle movement propelling the diver to the top of the platform

4

Conservation of energy

It is not possible o destroy or create energy- energy can only be converted from one for to another. Example: power plant- converts energy stored in coal to electricity.

5

Potential energy

The energy an object has because of its location or structure. The energy contained by water behind a dam or by a compressed springs.

6

Heat

A type of kinetic energy contained in the random motion of atoms and molecules

7

Entropy

Measure of the amount of disorder, or randomness, in a system. It's easy to increase the chaos in your room, but it requires significant energy to restore order once again.

Every time energy is converted from one form to another, entropy increases.

8

Chemical energy

The arrangement of atoms and can be released by a chemical reaction.

Example:
Carbs
Fats
Gasoline

9

Calorie

the amount of energy that can raise the temperature of 1 gram (g) of water by 1°C.

10

Kcal

Units of 1,000 calories

11

ATP- adenosine triphosphate

consists of an organic molecule called adenosine plus a tail of three phosphate groups

12

Metabolism

The total of all the chemical reactions in an organism

13

Enzymes

proteins that speed up chemical reactions without being consumed by those reactions.

14

Activation energy

activates the reactants and triggers the chemical reaction.

15

Substrate

An enzyme is very selective in the reaction it catalyzes. This selectivity is based on the enzyme’s ability to recognize a certain reactant molecule,

16

Active site

The active site is typically a pocket or groove on the surface of the enzyme

17

Induced fit

the entry of the substrate induces the enzyme to change shape slightly, making the fit between substrate and active site snugger. U

18

Enzyme inhibitors

substrate imposters that plug up the active site.

19

Diffusion

Movement for molecules spreading out evenly into the available space.

20

Passive transport

Diffusion of dye across a membrane is an example of passive transport—passive because the cell does not expend any energy for the diffusion to happen.

21

Concentration gradient

where the substance is more concentrated to where it is less concentrated.

22

Facilitated diffusion

Substances that do not cross membranes spontaneously—or otherwise cross very slowly—can be transported via proteins that act as corridors for specific molecules

23

Calorie

the amount of energy that can raise the temperature of 1 gram (g) of water by 1°C.

24

Kcal

Units of 1,000 calories

25

ATP- adenosine triphosphate

consists of an organic molecule called adenosine plus a tail of three phosphate groups

26

Metabolism

The total of all the chemical reactions in an organism

27

Enzymes

proteins that speed up chemical reactions without being consumed by those reactions.

28

Activation energy

activates the reactants and triggers the chemical reaction.

29

Substrate

An enzyme is very selective in the reaction it catalyzes. This selectivity is based on the enzyme’s ability to recognize a certain reactant molecule,

30

Active site

The active site is typically a pocket or groove on the surface of the enzyme

31

Induced fit

the entry of the substrate induces the enzyme to change shape slightly, making the fit between substrate and active site snugger.

32

Enzyme inhibitors

substrate imposters that plug up the active site.

33

Diffusion

Movement for molecules spreading out evenly into the available space.

34

Passive transport

Diffusion of dye across a membrane is an example of passive transport—passive because the cell does not expend any energy for the diffusion to happen.

35

Concentration gradient

where the substance is more concentrated to where it is less concentrated.

36

Facilitated diffusion

Substances that do not cross membranes spontaneously—or otherwise cross very slowly—can be transported via proteins that act as corridors for specific molecules

37

Osmosis

The diffusion of water across a selectively permeable membrane

38

Solute

a substance that is dissolved in a liquid solvent, and the resulting mixture is called a solution.

39

Solute+solvent=solution

a solution of salt water contains salt (the solute) dissolved in water (the solvent).

40

Hypertonic

The solution with the higher concentration of solute

41

Hypotonic

The solution with the lower solute concentration

42

Isotonic

Solutions of equal solute concentration

43

Osmoregulation

The control of water balance

44

Active transport

requires that a cell expend energy to move molecules across a membrane.

45

Exocytosis

During protein production by the cell , secretory proteins exit the cell from transport vesicles that fuse with the plasma membrane, spilling the contents outside the cell

46

Endocytosis

cell takes material in via vesicles that bud inward

47

Phagocytosis

Cellular eating- a cell engulfs a particle and packages it within a food vacuole

48

Liposomes

a minute spherical sac of phospholipid molecules enclosing a water droplet, especially as formed artificially to carry drugs or other substances into the tissues.

49

Signal transduction pathway

A set of chemical reactions in a cell that occurs when a molecule, such as a hormone, attaches to a receptor on the cell membrane. The pathway is actually a cascade of biochemical reactions inside the cell that eventually reach the target molecule or reaction.

50

Competitive inhibitor

a form of enzyme inhibition where binding of the inhibitor to the active site on the enzyme prevents binding of the substrate and vice versa.

51

Noncompetitive inhibitor

a type of enzyme inhibition where the inhibitor reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate

52

Transport protein

a protein that serves the function of moving other materials within an organism.

53

Dynamic equilibrium


a state of balance between continuing processes.

54

Recognize examples of potential energy and kinetic energy

Potential energy:
*Chemical energy from a battery
*elastic energy in a stretched rubber band
*gravitational potential energy. This is energy that is stored due to an object's position.

Kinetic energy:object depends on both its mass and velocity, with its velocity playing a much greater role.
*An airplane has a large amount of kinetic energy in flight due to its large mass and fast velocity.

55

Explain how changes in energy and/or transfers of energy affect entropy.

The second law of thermodynamics says that energy of all kinds in our material world disperses or spreads out if it is not hindered from doing so. Entropy is the quantitative measure of that kind of spontaneous process: how much energy has flowed from being localized to becoming more widely spread out (at a specific temperature).

56

Differentiate between a calorie and a "food calorie"

They are both units of energy, but the dietary Calorie (note the use of upper case 'C') equals 1000 'physics' calories. The physics calorie represents an amount of energy needed to raise (or lower) one gram of liquid water by one centigrade degre

57

Explain how the food we eat is converted to usable energy by cells

1-food (ingested) + air (inhaled)
2-carbohydrate+ oxygen&nitrogen
3-glucose+oxygen(final products of digestion and inhalation)
4-ATP(energy)+carbon dioxide(inhaled)+water(exhaled and excreted)

58

Explain how ATP provides energy to cellular work

When ATP is utilized to perform cellular work, the phosphate released by ATP becomes attached to another molecule. In this case depicted here, binding of the phosphate causes the sodium-potassium protein to do the work of moving sodium ions across the plasma membrane and out of the cell. When the phosphate is released, the protein changes shape again, pumping potassium ions into the cell.

59

List and describe or give examples of the three main kinds of work performed by cells.

*chemical work is building large molecules such as proteins. ATP provides the energy for the dehydration synthesis reaction that links amino acids together.
*mechanical work is the contraction of a muscle. In your muscle cells, ATP transfers phosphate groups to certain proteins. These proteins change shape, starting a chain of events which cause muscle cells to contract.
*transport work is pumping solutes such as ions across a cellular membrane. Again, the transfer of a phosphate group from ATP causes the receiving membrane protein to change shape, enabling ions to pass through.

60

Describe the ATP cycle

ATP is a really important short-term energy storage compound in cells. ATP contains 3 phosphates and when it is converted to ADP a phosphate is removed and energy is released that cells use for processes like movement, synthesis and active transport. Cells use ATP continuously, so after it is broken down it needs to be "put back together". This is why the ATP cycle is needed to produce ATP from ADP + P energy is needed. This energy comes from cellular respiration.

61

Describe the role of activation energy in a chemical reaction and explain how enzymes affect activation energy.

Enzymes are proteins that reduce the energy required to achieve the transition state. Enzymes reduce the activation energy through a process called catalysis. A biochemical reaction when an enzyme is present is called a catalyze do reaction. Catalysis can happen in different way ax enzymes can use the transfer of protons or electrons to the reactants to modify the state of the reactants.

62

Give a detailed explanation of how enzymes interact with their substrates.

When an enzyme binds its substrate,it forms an enzyme-substrate complex. This complex lowers the activation energy of the reaction and promotes its rapid progression by providing certain ions or chemical groups that actually form covalent bonds with molecules as a necessary step of the reaction process.

63

Give a detailed explanation of how the two different types of inhibitors described in your text interfere with enzyme activity.

Enzyme inhibitors are substances which alter the catalytic action of the enzyme and consequently slow down, or in some cases, stop catalysis. 3 types of common enzyme inhibition:
- competitive
- non competitive
- substance inhibition

64

Identify which cellular structure controls the flow of materials into and out of cells

Plasma membrane

65

List the six primary functions of membrane proteins

1-transport
2-enzymatic activity
3-signal transduction
4-intercellular joining
5-cell to cell recognition
6-attachment to the cytoskeleton and ECM

66

Describe the role of transport proteins in the movement of materials into and out of cells.

Transport proteins do much of the work in active transport. They are positioned to cross the membrane so one part is on the inside of the cell and one is on the outside. Only when they cross the bilayer are they able to move molecules and ions in and out of the cell. These proteins are very specific - one protein that moves glucose will not move calcium ions.

67

Differentiate among diffusion, facilitated diffusion and active transport.

*diffusion is the transport of solvent from higher concentration to lower concentration.
*faciliated diffusion -no energy is required.
*active transport there is energy requirement.

68

1-Explain the main difference between passive transport and active transport.
2-What is/are the key differentiating factor(s)? 3-What is the driving force is passive transport?
4-How is this different from active transport?

1- passive no ATP & active requires ATP
2-
3- The energy driving the movement of molecules during passive transport comes from differences in the concentration of the molecules on either side of the membrane with the molecules tending to move from the side of higher concentration to the side of lower concentration because of their net thermal movement.

69

Explain the relationship between osmosis and diffusion

Diffusion and osmosis both regard the dispersion of particles. By definition, water is the only substance that undergoes osmosis.

70

Can osmosis occur with and without a membrane present?

Osmosis again occurs because a concentration gradient exists and the membrane is permeable to water molecules; however, diffusion of solute does not occur even though a concentration exists because the membrane is impermeable to the large protein molecule.

71

Describe what happens when an animal cell is placed in an isotonic solution, a hypertonic solution, a hypotonic solution.

**hypertonic environment results in crenation, where the shape of the cell becomes distorted and wrinkled as water leaves the cell.
**hypotonic solutions cause them to swell, they become bloated and triple their original size.
**A cell in an isotonic environment is in a state of equilibrium with its surroundings.