3.1 + 4.1 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what do carbohydrates, proteins, lipids all contain?

A

carbon, hydrogen, and oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do all proteins contain?

A

nitrogen. some also contain sulfur.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are carbohydrates made up of?

A

simple sugars (ex. glucose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the ‘sugar’ we use in food called?

A

sucrose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are proteins made up of?

A

long chains of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are lipids made up of?

A

fatty acids and glycerol. there are 3 fatty acids in each lipid and the number of fatty acids vary in different lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

draw carbohydrates, lipids, and proteins

A

(see textbook pg 45)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the differences in structure of proteins and carbohydrates?

A

proteins are usually made up of several different kinds of amino acids but carbohydrates are usually made from one kind of simple sugar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why is water essential to living organisms?

A

water is the main part of the cytoplasm of the cell and the plasma of the blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

water is a good ____. why is it a good _____?

A

solvent. because many substances can dissolve in it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

starch is the ______ for plants?

A

storage molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what will happen when iodine/potassium iodide solution is mixed with a solution that contains starch?

A

the color of the iodide will change from brown —–> dark blue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the test for glucose called? what happens during it?

A

Benedict’s reagent. the Benedict’s solution is added to the sample (food) and heated to 95degrees Celsius (or in our class we did 80degrees Celsius).

if it changes color or forms a precipitate, this indicates the presence of reducing sugars (glucose).

green color: small amount of glucose
yellow color: medium amount of glucose
orange-red color: large amounts of glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what to be careful of when testing for glucose?

A

Benedict’s solution will cause the sample to change color for any reducing sugar. not just glucose. but glucose is the most common sugar so it’s okay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the test for protein and how is it conducted?

A

the biuret test. a sample of food is placed in a test tube and then an equal volume of buret solution is added. if it contains protein a blue ring will form. when it is shaken it will turn form blue to purple.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is used to test for fat? how does it work?

A

ethanol is used (after being mixed with water). the test depends on the fact that fats and oils don’t dissolve in water. if there is fat present it will create cloudy solution when mixed with the ethanol.

17
Q

what is a catalyst?

A

a substance that changes the speed of a reaction, usually making it faster

18
Q

what are enzymes?

A

catalysts that control metabolic reactions (biological catalysts). they are proteins.

19
Q

what is a biological catalyst?

A

a chemical that is found in living organisms and that changes the speed of a reaction.

20
Q

define substrate and product.

A

a substrate is a molecule that an enzyme joins with at the start of a reaction. substrate molecules are changed to product molecules during a reaction.

21
Q

what do we call the enzyme and the substrate?

A

they are complementary since they fit perfectly.

22
Q

what is the active site?

A

the space in the enzyme’s shape where the substrate fits. it makes it easier for the bonds inside the substrates to be rearranged to form the product.

23
Q

why does the enzyme not change after reacting with a substrate

A

because when the substrate changes to form a product the active sight does not change. the products gets released and the enzyme is free to bond with another substrate.

24
Q

enzymes are ___? and what does it mean?

A

enzymes are specific. it means that each enzyme only works with one substrate or a group of similar substrates.

25
Q

what is amylase, proteases, lipases?

A

amylase is a type of carbohydrate enzyme produced in the mouth

proteases are digestive enzymes that break down proteins into smaller units

lipases are digestive enzymes that break down lipids in foods

26
Q

how does an enzyme cause a substrate molecule to change into product molecules?

A

the sequence of amino acids in the amino acid chain determines the way the chain will fold up to make the three dimensional structure of the protein.

27
Q

what is the particular temp. at which enzymes work best called?

A

optimum temperature.

28
Q

what is the usual optimum temperature for enzymes in the core (center) of the body such as the liver, kidneys, and lungs?

A

around 37degrees C

29
Q

what happens when an enzyme is far form it’s optimum temp.

A

when it’s too low, the enzymes work more slowly, and when it’s too high the enzyme changes so it won’t work. it is called being denatured.

30
Q

how to investigate the effect of temp. on enzymes?

A

do the iodine solution experiment but this time put the solutions in different temp. water baths and see what happens.

31
Q

what is kinetic energy?

A

it is the energy of moving particles. particles that have a greater kinetic energy move faster. the kinetic energy of atoms held within larger molecules will cause them to vibrate.

32
Q

an enzyme and a substrate molecule can only form an enzyme-substrate bond when…

A

they bump into each other with sufficient energy (how high their kinetic energy is) and the substrate fits into the active site. so at a low temp they both move slowly so it’s harder for them to join to start the reaction and if it’s too high than the enzyme could be damaged because of ecssesive bumping.

32
Q

an enzyme and a substrate molecule can only form an enzyme-substrate bond when…

A

they bump into each other with sufficient energy (how high their kinetic energy is) and the substrate fits into the active site. so at a low temp they both move slowly so it’s harder for them to join to start the reaction. If it is beyond the optimum temp than they are vibrating so much they change the shape of the active site which lowers the rate of reaction and chances of them bonding. And if it’s too high than the enzyme could be damaged because of too much bumping, breaking.

33
Q

enzymes and pH (basic stuff)

A

enzymes also often work best at a particular pH, called their optimum pH.

34
Q

what can pH do?

A

pH can slow down the rate of action of the enzyme or even denature (destroy) it.

35
Q

different enzymes have different ___

A

pHs (based on where they are normally found in the body)

36
Q

know the experiments for pH

A

on classroom and on page 57-58

37
Q

what causes the enzyme’s 3D shape? (that the substrate can fit into) and what does pH have to do with it (effect of pH)

A

proteins are made up of amino acids and the amino acids are joined together in a chain with folds up to cause the 3D shape of an enzyme.

some of the interactions between amino acids in the enzyme depend on the pH of the surround solvent (ex. water is a solvent) so if the pH changes too much from the optimum than the enzyme is in danger of denaturing or the substrate not fitting well so the reaction being slow or not being able to occur.