ch. 5 lecture notes

Cholesterol

-most common steroid in humans -precursor to steroid hormones, such as reproductive hormones -mostly insoluble in water -found in bile

What is different between fats and phospholipids

1. phospholipids have only 2 fatty acid tails instead of 3 2. phospholipids have a polar group 3. phospholipids usually have at least one unsaturated bond

Carbohydrates follow what formula?

1:2:1 for C:H:O

What do steroids look like

4 carbon rings

hydroxyl group of carbon-1 is above the ring?

Beta

What are two (optical) isomers of glucose, and have different properties?

Galactose and mannose

What is chitin made of and what type of bonds?

N-acetylglucosamine that also form hydrogen bonds

Phosphatidylcholine

Phospholipids undergo dehydration synthesis to join fatty acids, glycerol and polar head group

Are phospholipids amphiphillic molecules?

Yes

What does a trans isomer look like?

across

hydrolysis

adds water to break a molecule apart

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

adenine and guanine

What does a cis isomer look like?

adjacent

What type of molecule can interact with oils and water molecules

amphilic molecules

Phospholipids are ___________ molecules

amphillic

What are lipids?

are fats, phospholipids and steroids that mix poorly with water

What is a phophoanhydride bond?

bond between the phosphates in the ATP

Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.

carbonyl (-C=O); hydroxyl (-OH)

The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is __________.

cholesterol

What builds sex hormones?

cholesterol

what is in bile?

cholesterol, Deoxycholic acid, taurocholic acid, phospholipid

How are monosaccharides joined?

covalent bonds

What do steroids do for our cells?

give structure

One characteristic shared by sucrose, lactose, and maltose is that __________.

they are all disaccharides

What is a three fatty acid tails attached to a hydroxyl of glycerol called?

triglyceride

Name two monosaccharides?

Aldose and Ketose

hydroxyl group of carbon-1 is below the plane of ring

Alpha

alpha beta glucose

Alpha: hydroxyl group of carbon-1 is below the plane of ring Beta: hydroxyl group of carbon-1 is above the ring

What other polysaccharide is similar to cellulose?

Chitin

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide __________.

Chititn

What makes hormones?

Cholesterol

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

DNA

What joins fatty acids to glycerol?

Dehydration synthesis

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?

Lipids

Starch has what type of linkage of glucose?

a 1-4

Sugars are molecules that have __________ C:H:O and are called __________.

a 1:2:1 ratio of; carbohydrates

Dehydration synthesis

a chemical reaction in which two molecules become covalently bonded to each other with the removal of water

The peptide bond is __________.

a covalent bond joining amino acids together to form a polypeptide

The components of nucleic acids are __________.

a nitrogenous base, a pentose sugar, and a phosphate

What does amphiphiliic mean?

a term describing a chemical compound possessing both hydrophillic (water-loving, polar) and hydrophobic (water -hating) properties.

alpha beta glucose are in equilibrium in aqueous solutions at a ration of __________

a:B 36:64

What is the most important and common steroid?

cholesteral

When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have __________ and are __________ at room temperature.

cis double bonds; liquids

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

covalent

What do trans fats do to HDL (good cholesterol)?

decrease

How are fatty acids joined to glycerol?

dehydration synthesis

In living organisms, DNA exists as a __________ with the strand(s) __________.

double helix; running antiparallel

True or false, Monosaccharides usually exist in linear form?

false

In fats what does the double bond to carbons cause the fat to do?

kink, and make it a liquid because they can't stack on top of each other

where is bile found?

liver

What is the monomer of carbohydrate?

monosaccharides

nucleotides have?

nitrogenous base, 5-carbon sugar (ribose or deoxyribose) phosphate group

Are fats polymers?

no

Can humans break down B 1-4 bonds found in cellulose?

no only bacteria and other microorganisms can

Can we break down molecules in their polymerized form?

no, we can't break them down

is cholesterol nonpolar or polar

nonpolar-because it doesn't interact with water, classifying it as a lipid

Nucleic acids are polymers of what?

nucleotide

Galactose an mannose are what type of isomers of glucose?

optical

What are bacteria cell walls composed of?

peptidoglycan

polymer of amino acids?

polypeptides

How do phospholipids and triglycerides differ?

they differ from triglyceride by polar head and usually have at least on unsaturated carbon

Fats are made up of what?

three fatty acids linked to one glycerol molecule; called triglyceride

In a dehydration synthesis reaction, __________ is always formed as a by-product of the reaction.

water

__________ is always involved in hydrolysis reactions.

water

Why would a phospholipid have one unsaturated fatty acid

you wouldn't want you membranes of cells to be solid immovable structure, you would want it to be able to move

What is carbon used for?

emulsifier gets thing to dissolve well its found in bile

Carbohydrates are used in our bodies mainly for __________.

energy storage and release

"polymer "fatty acids" (lipids are do not have monomers or polymers)

fats and lipids

Lipids are composed of what three molecules part?

fats,membrane lipids, steroids

Phospholipids are composed of three molecule parts?

fatty acids, glycerol, polar group

What does cholesterol do for cell membranes?

give structure

Name monosacchrides

glucose, frutose, glactose, ribose, dioxyribose

A polysaccharide that is used for storing energy in human muscle and liver cells is __________.

glycogen

How are monosaccharides are joined together?

glycosidc linkage by dehydration synthesis

What joins disaccharides together?

glycosidic bond

How are disaccharides joined?

glycosidic bonds

The subunits (monomers) in cellulose are linked together by __________.

glycosidic linkages

Cellulose is strengthened by what type of bonds amoung parallel strands?

hydrogen bonds

Which is the term for compounds that do not mix with water?

hydrophobic

What do trans fats do to LDL (bad cholesterol)?

increase

What is peptidoglycan?

is similar to chitin, but includes alternating N-acetyl-murmaic acids subunits that are covalenty crosslinked

Why does starch use a repeating a1-4 linkage of glucose?

it is created exclusively by plants and used as form of energy storage

The lipids that form the main structural component of cell membranes are __________.

phospholipids

what are most membranes made up of?

phospholipids

where do carbohydrates come from?

photosynthesis, carbon dioxide and water put togeather

What are the polymer of carbohydrates?

polysaccharides

polymer of sugar?

polysaccharides

What causes carbohydrates to form into a ring?

putting them in water

if fat is saturated should it be liquid or solid?

solid

name polysacchrides

starch, cellulose, chitin, glycogen

What do fats do?

storage of energy and insulation protection

name disacchrides

sucrose, maltose, lactose

What hormones does Cholesterol create?

testosterone, estrogen, cortisone, petosterone