Learning goal one (case 1)

Question 1

what are the types of fats (citeria: form, function)

Answer 1

simple lipids (triglycerides, waxes),; (2) complex lipids (phospholipids glycolipids.); (3) steroids; and (4) prostaglandins, thromboxanes, and leukotrienes.

triglycerides (saturated, unsaturated(polyunsaturated,mononunsaturated), trans, cholesterol, phospholipids, steroids)

by function:
-storage:
(adipose tissue with triglycerides molucules),
-membrane components:
(because of its lipids insoulubelity its the best to sperate compartments containing aqueos solutions , The polar groups they contain are much smaller than their alkane-like (nonpolar) portions, these nonpolar portions provide the water-repellent, or hydrophobic, property),
-messengers:
primary such as steroid hormones
secondary such as prostaglandis,thromboxanes

Question 2

Lipids proporties

Answer 2

insoulable in water, soluble in nonpolar solvents such as diethyl ether.

Question 3

how much energy does burning fat produce? comparing to carbohydrate? which one is has the piorority of storage in animals or prefered?

Answer 3

burning fat produces about 9 kcal/g while carbohydrate 4 kcal/g, animal bodies prefer to store energy in the form of fat because of the high amount of energy.

Question 4

which property makes lipids a functional compenent in the membrane, explaination related to its structure

Answer 4

lack of water solubility, because our body is heavily based on water most of the body constituents are soluble in water, to seperate its compartments that contains aqueous solutions. the phospholipids and glycolipids which are complex lipids are contained of a polar small group (hydrophilic head group that interact with water and consist of (Polar group, phosphate, glycerol) and two non polar long hydrocarbon chains of two fatty acid (saturated and non saturated) unlike triglycerides with three fatty acids, and becasue the non polar part is the biggest part of phospholipids they are non-soluble in water. Although polar themselves, are buried! in a nonpolar environment, which makes the triglycerides insoluble in water.
The unsaturated fatty acids prevent the tight packing of the hydrophobic chains in the lipid bilayer, thereby providing a liquid-like character tothe membranes. This property of membrane fluidity is of extreme importance because many products of the body’s biochemical processes must cross the membrane, and the liquid nature of the lipid bilayer allows such transport
The lipid part of the membrane serves as a barrier against any movement of ions or polar compounds into and out of the cells.

Cholesterol, another membrane component, is largely hydrophobic but does contain a small polar portion. The poral portion of cholesterol is also oriented towards the inner and outer surface of the membrane.

Question 5

structure triglycerides, with common features

Answer 5

tirglycerides are triesters consist of the alcohol glycerol always and the more number of fatty acids (saturated no C=C (CH3 (CH2)n COOH)or unsaturated yes C=C ).

common features:
1. Fatty acids are practically all unbranched carboxylic acids.
2. They range in size from about 10 to 20 carbons.
3. They contain an even number of carbon atoms.
4. Apart from the COOH group, they have no functional groups, except that some do have double bonds.
5. In most fatty acids that have double bonds, the cis isomers predominate.

Question 6

meaning of cis configuration of fatty acids, its feature, impact on its mixture consitency.

Answer 6

When the two hydrogen atoms stick out on the same side of the chain, the fatty acid is said to be in a cis configuration. This results in a kink due to the two hydrogen atoms repelling each other slightly. The more double bonds in the cis configuration, the less flexible is the fatty acid. Thus, the linoleic acid with two double bonds would have a more pronounced bend compared with the oleic acid that has only one double bond. The kink or the bend on the fatty acid molecule prevents them from stacking together and becoming solid in room temperature (oile). The cis is the natural and the common configuration of unsaturated fatty acids.

Question 7

why the body contains only even-numbered triglycerides acids

Answer 7

Only even-numbered acids are found in triglycerides because the body builds these acids entirely from acetate units and therefore puts the carbons in two at a time.

Question 8

what happens when triglycerides interact water

Answer 8

When in contact with water the triglyceride molecules rearrange themselves to lower the energy penalty due to the interface, with the glycerol groups facing the water phase

Question 9

advantage of having hydrophilic head in triglyceride

Answer 9

this allows it form a phosphid bilayer, with the water-philic portions sticking outwards, towards the outside of the cell, and towards the inside of the cell, with the middle part, as hydrophobic.

Question 10

structure of waxes

Answer 10

Plant and animal waxes are simple esters, As in fats, the acid portions of the esters consist of a mixture of fatty acids; the alcohol portions are not glycerol, however, but rather simple long-chain alcohols. Waxes generally have higher melting points than fats (60 to 100°C) and are harder.

Question 11

why waxes are solid

Answer 11

because of the huge molecular weight

Question 12

complex lipids

Answer 12

constitute the main components of membranes. Complex lipids can be classified into two groups: phospholipids and glycolipids

Question 13

types of phospholipids and the difference

Answer 13

glycerophospholipids and sphingolipids,
glycerophospholipids, the alcohol is glycerol. In sphingolipids, the alcohol is sphingosine.

Question 14

glycolipids, ( needs to devid this question to subquestions! )

Answer 14

Glycolipids are complex lipids that contain carbohydrates, are membrane compound cells throughout the body.
The backbone is glycerol. Two of its three hydroxyl groups are esterified by fatty acids.
The thrids group is esterified not by a fatty acids, but by a phosphate group, which is also esterified to another alcohol. If the other alcohol is choline (a quaternary ammonium compound) the glycerophospholipids are called phosphatidylcholines (lecithin).
Lecithin has a negatively charged phosphate group and a positively charged quaternary nitrogen from the choline. These charged parts of the molecule provide a strong hydrophilic head, whereas the rest of he molecule is hydrophobic.
Thus, when a phospholipid such as lecithin is part of a lipid bilayer, the hydrophobic tail points towards the middle of the bilayer and the hydrophobic heads line both the inner and outer surfaces of the membranes.
Another important group of glycerophospholipids is the phosphatidylinositol (PI). In PI, the alcohol inositol is bounded to the rest of the molecule by a phosphate ester bond. Such compounds not only are integral structural parts of the biological membranes, but also serve as signaling molecules in chemical communications. (Phosphoinositides function in a diverse array of cellular activities. They include a role as substrate for lipid kinases and phospholipases to generate second messengers, regulators of the cytoskeleton, of enzymes and of ion channels, and docking sites for reversible recruitment of proteins to membranes.)
What is the role of phosphatidylcholine?
Phosphatidylcholine (PC) is an important component of the mucosal layer of the colon and acts as a surfactant within the mucus to create a hydrophobic surface to prevent bacterial penetrance

Question 15

advantage of having unsaturated fatty acid in cells membrane and organelles membranes

Answer 15

The unsaturated fatty acids prevent the tight packing of the hydrophobic chains in the lipid bilayer, thereby providing a liquid-like character tothe membranes.

Question 16

why unsaturated acids have lower melting points than saturated fatty acids

Answer 16

The unsaturated fatty acids prevent the tight packing of the hydrophobic chains in the lipid bilayer, thereby providing a liquid-like character tothe membranes.
This effect is similar to the one that causes unsaturated fatty acids to have lower melting points than saturated fatty acids

Question 17

protein molecules in the membrane clasified of there position in the phospholipids bilayer

Answer 17

Peripherla proteins, which are suspended on the surface, integral protein, which are partly or fully embeded in the bilayer, both stickout of the membrane, Others are thoroughly embedded, going through the bilayer and projectingfrom both sides

Question 18

Structure of steroids

Answer 18

the steroids, any of a class of natural or synthetic organic compounds characterized by a molecular structure of 17 carbon atoms arranged in four rings. Steroids are thus completely different in structure from the lipids. Note that they are not necessarily esters, although some of them are.

Question 19

Fluid mosaic model of membrane advantage

Answer 19

Fluid mosaic model of membrane allows the passage of nonpolar compounds by diffusion, as these compound are soluble in the lipid membranes.
The fluid mosaic model describes the cell membrane as a tapestry of several types of molecules (phospholipids, cholesterols, and proteins) that are constantly moving. This movement helps the cell membrane maintain its role as a barrier between the inside and outside of the cell environments

Question 20

Cholesterol function and poperties

Answer 20

The most abundant steroid in the human body, and the most important, is cholesterol. Cholesterol serves as a plasma membrane component in all animal cells. Its second important function is to serve as a raw material for the synthesis of other steroids, such as sex and adrenocorticoid hormones.

Question 21

how is fats and cholesterol are transported

Answer 21

fats and cholesterol are transported by Lipoproteins

Question 22

describe the structure of lipoproteins

Answer 22

Most lipoproteins contain
a core of hydrophobic lipid molecules
surrounded by a shell of hydrophobic lipid molecules surrounded by a shell of hydrophilic molecules such as proteins and phospholipids.

Question 23

types of lipoprotein with its precentege of proteins and fats and if its good or bad

Answer 23

• hhigh density (كثافة) lipoprotein HDL (good cholesterol), 33% protein and 30%cholesterol and cholesteryl esters.
  -Low-density lipoproteins LDL (bad cholesterol), 25% protein, 50% holesterol and choleseryl esters.
  -very-lowdensity lipoprotein VLDL, mostly carries triglycerides (fats) synthesized by the liver.
  -Chylomicrons, which carry dietery ats that were made in the intestines (darmkanaal)

Question 24

ADRENOCORTICOID HORMONES, which gland, types, function,

Answer 24

The adrenocorticoid hormones are products of the adrenal glands. We classify these hormones into two groups according to function:
Mineralocorticoid regulate the concentrations of ions (mainly K+ and Na+).

Glucocorticoids control carbohydrate metabolism.

Question 25

what is aldosteron? its function?

Answer 25

Aldosterone is one of the most important mineralocorticoids.
Increased secretion of aldosterone enhances the reabsorption of Na+ and Cl- ions in the kidney tubules and increased the loss of K+. Because Na+ concentration controls water retention in the tissues, aldosterone controls tissue swelling.

Question 26

whatis Cortisol? its function?

Answer 26

Cortisol is the major glucocorticoid. Its function is to increase the glucose and glycogen concentration in the body. This accumulation occurs at the expense (the cost) of other nutrients.

Question 27

SEX HORMONES explain briefly relation to cholesterol and function

Answer 27

The most important male sex hormone is testosterone. This hormone, which promotes the normal growth of the male genital organs, is synthesized in the testes from cholesterol. Female sex hormones, the most important of which is estradiol are synthesized from testosterone by aromatization of the A ring.
Aromatization is the biochemical process in which aromatase catalyzes the conversion of testosterone into estradiol, the fundamental pathway for the synthesis of estrogens. When enhanced, it can lead to hyperestrogenism, a well-known risk factor for gynecological cancers.

Question 28

basis molecular structure of a sugar

Answer 28

structureThe basis molecular structure of a sugar is a monosaccharide- a carbohydrate that cannot be hydrolysed to a simpler compound, with the formula CnH2nOn.
These have a between 3 and 7 carbons arranged in an open structure or a ring. If there is an open structure, the carbohydrate will contain an aldehyde ( R−CH=O) or ketone (R₂C=O) group. This converts to an ether bond (R-O-R) if the molecule is synthesised to a ring structure. Hexose sugars are by far the most abundant within nature e.g. Glucose

Question 29

what bond is between monosacharides, from which reaction they form

Answer 29

glycocidic bonds, condensation reaction, as water is eliminated; it is made from the OH of one glucose and the H (of the OH group on C4) of another glucose molecule. The remaining oxygen of the OH on C4 joins to the other carbon forming a glycosidic bond. As the link is between Carbons 1 and 4, it is called a 1,4-glycosidic bond.
There are are two types of glycosidic bonds - 1,4 alpha and 1,4 beta glycosidic bonds. 1,4 alpha glycosidic bonds are formed when the OH on the carbon-1 is below the glucose ring; while 1,4 beta glycosidic bonds are formed when the OH is above the plane. When two alpha D-glucose molecules join together a more commonly occurring isomer of glucose compared to the L-glucose, form a glycosidic linkage, the term is known as a α-1,4-glycosidic bond.

Question 30

advantage of having 10% 1,6-glycosidic bonds within glycogen

Answer 30

This makes the structure more branched, so it can be hydrolysed (and thus release energy) more quickly.

Question 31

what make the range of possiple structure of a polysaccharide so wide

Answer 31

branches can occur through the hydroxyl groups attached to the basic monosaccharide ring. The number of hydroxyl groups combined with the hypothetical thousands of monosaccharide units means that the number of possible structures of a polysaccharide is in the millions.

for example glycogen: Glycogen is a chain of glucose subunits held together by 1→4-glycoside bonds, but it is a highly branched structure.
Every 8 to 10 glucose units, branches are joined by 1→6 glycoside bonds.

Question 32

breaking glycosidic bonds

Answer 32

Breaking the bond is a hydrolysis reaction (requiring water) returning an OH to one carbon and a H to the other
All of the reactions involved in making and breaking glycosidic bonds are catalysed by enzymes

Question 33

functions of saccharides or carbohydrates

Answer 33

provides chemical energy, (glucose, starch, glycogen)
compnents of supportive structure in plants (cellulose)
crustacean shells (chitin)
connictive tissue in animals ( acidic polysaccharides)
essential components of nuclei acids (D-ribose, 2-deoxy-D-ribose)

Question 34

the most abundant disaccharide

Answer 34

sucrose, It is obtained from the juice of sugarcane and sugar beets (يتم الحصول عليها من عصير قصب السكر وبنجر السكر)

Question 35

why is the most abundant disaccharide a non-reducing sugar

Answer 35

Because the anomeric carbons of both the glucopyranose (glucose) and the fructofuranose units are involved in formation of the glycosidic bond, neither the monosaccharide unit is in equilibrium (evenwicht) with its open-chain form. Thus, sucrose is a non-reducing sugar. (no hydrolysing with H2O)
it also lacks a free aldehyde or ketone group thats why it cant be reduced.

Question 36

what is an anomeric carbon

Answer 36

An anomeric carbon can be identified as the carbonyl carbon (of the aldehyde or ketone functional group) in the open-chain form of the sugar. It can also be identified as the carbon bonded to the ring oxygen and a hydroxyl group in the cyclic form

Question 37

the sugar present in milk, reducing or non-reducing, why? which glycocidic bond it has?

Answer 37

Lactose which is a disaccharide reducing sugar, because the cyclic hemiacetal of the D-glucopyranose unit is in equilibrium with its open chain form and can be oxidized to a carboxyl group, it has 1,4-glycocidic bond, between 4-C in beta-D-glucopyranose and 1-C in beta-D-Galactopyranose.

Question 38

what is hemiacetal

Answer 38

A hemiacetal or a hemiketal have the general formula R1R2C(OH)OR, where R1 or R2 is hydrogen or an organic substituent. They generally result from the addition of an alcohol to an aldehyde or a ketone, although the latter are sometimes called hemiketals. Most sugars are hemiacetals.

Question 39

sugar present in malt, reducing or non, why? what bond?

Answer 39

Maltose, disaccharide, reducing, it has a free aldehyde and the hemiacetal group on the right unit of the D-glucopyranose is in equilibrium with the free aldehyde and can be oxidized to a carboxylic acid (R-COOH)

Question 40

general structure of monosaccharides?

Answer 40

Monosaccharides have the general formula CnH2nOn, with one of the carbons being the carbonyl group of either an aldehyde or a ketone. Monosaccharides containing an aldehyde group are classified as aldoses those containing a ketone group are classified as ketones.

Question 41

D- and L- Monosaccharides, what does it mean

Answer 41

D-monosaccharide – a monosaccharide that, when written as a Fischer projection, has the – OH group on its penultimate ( = voorlaatste) carbon to the right.
L-monosaccharide – a monosaccharide that, when written as Fischer projection , has the – OH group on its penultimate to the left.

Question 42

what is furanose and pyranose

Answer 42

pyranose are sugars with 6 carbones ring and furanose with 5

Question 43

why sugar in fruit is more helthy than refined sugar in doughnat

Answer 43

because the fibers in fruit slow down the sugar digistion it contains, in contrast with refined sugar that give you a spike of insuline and glucose in blood and lead to health problems.
natural nutrition come with other nutritions that are good to the body and prevent rapid spike of glucose in blood becasue the body digist them slower than concentrated sugar usualy fructose

Question 44

digestion of fats

Answer 44

in the oral cavity:
through the exposure to lingual lipase, which are secreted by glands in the tongue.
in the stomach: through the effects of both lingual and gastric enzyme. emulsification of dietary fat and fat-soluble vitamins, with peristalsis a major contribution factor.
Crude emulsions of lipids enter the duodenum as fine lipid droplets and then mix with bile and pancreatic juice to undergo marked changed in chemical and physical form.

Emulsification continues in the duodenum along with hydrolysis and micellization in preparation for absorption across the intestine wall.
Bile and pancreatic juice provide pancreatic lipase, bile salts, and colipase, which function cooperatively to ensure the efficiency of lipid digestion and absorption.

Question 45

Sugar digestion

Answer 45

During digestion, starches and sugars are broken down both mechanically (chewing) and chemically (enzymes) into the single units glucose, fructose, and/or fructose, which are absorbed into the blood stream and transported for use as energy throughout the body.
Digestion of starches into glucose molecules starts in the mouth, but primarily takes place int eh small intestines by the action of specific enzymes secreted from the pancreas (e,g, α-amylase and α-glucosidase). Similarly sucrose, lactose, and maltose are also broken down into single units by specific enzymes.
The end products of sugars and starched digestion are the monosaccharides glucose, fructose, and galactose. Glucose, fructose and galactose are absorbed across the membrane of the small intestine and transported to the liver where they are either used by the liver, or further distributed to the rest of the body

Question 46

PASSIVE TRANSPORT

Answer 46

simple diffussion: a molecule moves directly through the membrane without interacting with another molecule. Small, uncharged molecules can pass through membranes via simple diffusion. The rate of movement through the membranes is controlled by the concentration differences across the membrane
Larges molecules and ions cannot pass through a membrane using a carrier protein by simple diffusion.

facilitated diffusion: large molucules use protein carrier, where a pore created by folding the backbone and side chains.

Question 47

active transport

Answer 47

against concentration gradient.
primary active transport: hydrolysis one ATP required to move the molecule against concentration gradient.

Sodium-potassium ion pump:
the concentration of K+ is higher inside a cell than in extracellular fluids, but the concentration of Na+ is lower inside the cell than out.
to move these ions agains there concentration gradient, requires ATP hydrolysis.
the same protein catalyse the transport and the ATP hydrylisis.
ATP, ADP and P(the reactants) remain within the cell, and the phosphate becomes covalently bonded to the transport protein for part of the process.

steps:
1- one subunit hydrolyzes ATP and transfer the Phosphate to a side chain in another subunit

2- thre Na+ bind in the inside part of the protein, phosphorylation, changes the form of the protein, open a pore and releases three NA to the extracellular fluid.

3- 2 K+ bind to the outside part of the protein, which is still phosphorylated.

4- form change, after phosphate released becasue of hydrolyzation, allows the 2 K+ to go intracellular.

Question 48

how do carrier proteins work if there is no K+ but a high concentration of Na+ in the extracellular fluid.

Answer 48

ADP phosphorylation produces ATP, and still need reaearches of what happens :)

Question 49

advantage of micelles

Answer 49

helps th body absorbs vitamins, and help small intestine to absorb essential lipids and vitamines from the liver and gal bladder.
carries coplex lipids such as lecithin and lipids soluble vitamine (A, D, E, K) to the small Intestine.

Question 50

lipids transport

Answer 50

blood contain chylomicrons lipids, formed within the intestinal mucosal lining derived from stored depots.
such as liver and adipose tissue.
because lipids are hydrophopic they iuse lipoproteins to transfer through the bloood fluid.

Question 51

lipoprotein factor that determains its density in blood

Answer 51

if the lipoprotein have more lipids than protein its density decrease and, vise versa

Question 52

main lipoprotein in blood

Answer 52

chylomicrons, (VLDL), LDL, HDL

Question 53

where are lipoprtoeins are synthesized

Answer 53

Chylomicrons are synthesized in the small intestine form dietary fat, and VLD, LDL, and DHL are synthesized in the liver and small intestine.

Question 54

how chylomicrons functions

Answer 54

enter the liver and get packaged to VLDL, to help by transportation of cholesterol to tissues

Question 55

HDL function

Answer 55

reverse transport or removal of cholesterol, from a tissue to the liver to LDL,
While in the serum, the free cholesterol in HDL are converted to cholesteryl esters.
These esterified cholesterols are delivered to the liver for synthesis of bile acids and steroid hormones.

in a selective lipid uptake, the HDL binds to the liver cell surface and transfers its cholesteryl ester to the cell.

the remaining HDL reenter the blood circulation, It is desirable to have a high level of HDL in the blood because of the way it removes cholesterol from the blood stream.

Question 56

how cholesterol transports

Answer 56

transport of cholesterol begins in the liver as a VLDL large partical, its core contain triglycerides and cholesteryl esters, surrounded by phospholipids and proteins. the VLDL is carried in the serum.

Question 57

how do VLDL relases triglycerides in fat and musclaris textus

Answer 57

When the capillaries reach muscle or fat tissue, the triglycerides and all proteins except a protein called apoB-100 are removed from the VLDL. Because of the removal of fat, its density increases and becomes LDL.

Question 58

function of LDL

Answer 58

carries cholesterol to the cells, through specific LDL receptor, that line the cell surface, in certain areas called the coated pits.
after binding LDL goes intracellular space by endocytosis,
enzymes breaks down the lipoprotein,
cholesterol liberated from cholesteryl esters. cholesterol is now component of the membrane

Question 59

what are coated pits

Answer 59

certain areas in the membrane that has LDL receptors concentrated.

Question 60

essential fatty acids

Answer 60

A fatty acid that cannot be synthesized by the body (or not in adequate amounts) and is therefore essential to the diet. In humans,
alpha linoleic acid and linolenic acid are the primary essential fatty acids.
There are two families of EFA, omega-3 (ω-3) and omega-6 (ω-6).

Question 61

fats nomenclature

Answer 61

delta:
number c
number of double bonds
number of c from carboxyl acid to the first c in the double bond

omega:
same:: but
*Carbons are counted from the methyl (omega) end instead of the carboxylic acid end
*The omega symbol is used instead of the delta symbol

Question 62

sugar nomeclature (continue!!!)

Answer 62

-how many c
-type of functional group, aldyhede (R-CH=O)
Ketone (R-C=O), in addition to alcohols
-the open chain vs the cyclin structure

3 to 9 monosaccharides are oligosaccharides

above that polysaccharides

Question 63

common sugars

Answer 63

Glucose:
glycogen:

Question 64

what types of fats are unhealthy and why

Answer 64

saturated and trans fats, beasue they promote the formation of LDL and decrease HDL, that cause blood vessels diseases, in high amounts.