carbohydrates (b1- foundation) Flashcards

Question

how many chiral centers are in glucose & what is the significance?

Answer 1

**4 chiral centers** **significance**: gives isomers - D- glucose is beneficial for the body whereas L-glucose is used in artificial sweeteners (*good for diabetes b/c will enter blood and not get metabolized*) notes says to know this significance of D & L isomers

Answer 2

change in optical rotation that happens when a sugar is dissolved in water - **switches between its α and β forms** the 2 forms **interconvert** and as they interconvert, the way they rotate light also changes - pure α-D-glucose has rotation of **+112.2º** - pure β-D-glucose has rotation of **+18.7** overtime, the mixture at equilibrium equals **+52.7°**

Answer 3

through **glycosidic linkage** by a condensation reaction

Answer 4

**O-glycosidic linkage**: formed b/w anomeric carbon of 1 sugar and the OH group of another sugar or molecule *2 types* **α-linkage**: OH from anomeric carbon was down (two alphas meet) **β-linkage**: OH from anomeric carbon was up (1 beta and 1 alpha meet)

Answer 5

because when you break (hydrolyze) sucrose into glucose and fructose, the **direction of light rotation changes**, or inverts sucrose is (-) but when break it down, fructose overpowers so it becomes (+) *only sugar that does this* **enzyme used for hydrolysis**: sucrase or invertase

Answer 6

Glucose – fructose α 1→ 2 β *1st carbon of glucose, 2nd carbon of fructose* + free reducing groups not available disaccharide since made of 2 monosaccharides

Answer 7

has a **free anomeric carbon** (anomeric carbon is not linked to anything else through glycosidic linkage) b/c whatever anomeric OH is free is whats going to make a bond *all monosaccharides are reducing sugars but all disaccharides are not*

Answer 8

galactose + glucose β-1 – α-4 *1st carbon of galactose w/ 4th carbon of glucose* *lactose is diff from lactate/lactic acid- thats whats produced as a result of anaerobic respiration*

Answer 9

glucose + glucose α1→ α4 (straight chain)

Answer 10

glucose + glucose - alpha -1, alpha 6 linkage (branched chain b/c muscles dont have that much space for straight chain so branched to compact them together)

Answer 11

homopolysaccharides: same monosaccharide units **storage homopolysaccharides**: starch, glycogen, inulin, dextrin, dextran **structural homopolysaccharides**: cellulose, chitin

Answer 12

**biochemical significance**: plants storage energy form, non-reducing sugar (*b/c too compacted that it's not rlly free anymore- non reducing bc of compaction not structure*) **linkage**: α1→ α4 & α1→ α6 **components**: 2 subunits - amylose & amylopectin

Answer 13

**1. amylose (15-20% of starch)**: long unbranched chain of thousands of D-glucose units - forms helices (coils) that trap iodine molecules (*which is why iodine test shows presence of starch*) - digested by *amylases* that hydrolyze alpha-1,4-glycosidic bonds **2. amylopectin (80-85% of starch)**: also made of D-glucose but **highly branched** - branches created by α-1,6 glycosidic bonds every 24-30 glucose units - most of the starch in **plants** is in this form - digested by **debranching enzymes** that hydrolyze α-1,6

Answer 14

**salivary amylase** (mouth) and **pancreatic amylase** (intestine) break **α-1,4 bonds** randomly - produces smaller chains called **dextrins** that are eventually broken into **maltose** and **glucose**

Answer 15

storage form of glucose in animals - large, branched molecule made entirely of **D-glucose** units **structure**: very similar to amylopectin but with more branches and more compact (has **α-1,4** & **α-1,6 linkages** - at the center of each glycogen molecule is a protein called **glycogenin** (is like a primer- starting point where glucose molecules begin to attach) **importance**: highly branched so more compact (can store more glucose in a small space) **storage**: 5% weight stored in liver, 1-2% stored in muscle

Answer 16

**liver**: maintains blood glucose levels **muscle**: used for muscle energy only, muscles dont have enzyme **G6P** so they **cant convert stored glucose into free glucose** to release into the blood - *muscles are very selfish, they dont like to donate, keep everything for themselves*

Answer 17

branching in glycogen

Answer 18

made of many D-glucose units (polysaccharide), found in plants esp cell walls, most abundant organic compound on earth **structure**: joined by **β-1,4 glycosidic bonds** = long, straight, unbranched chains = its really strong!!

Answer 19

humans lack enzyme **cellulase** (or cellobiase) so cant break β-1,4 bonds in cellulose but it acts as **roughage (fiber)** for us **health benefits of roughage**: 1. increases bowel motility 2. prevents constiptation & hemorrhoids 3. lowers blood cholestrol (by interfering with its absorption) 4. industrial uses (paper, cotton, linen)

Answer 20

**linkage**: β-1,2 glycosidic linkages - made entirely of D-fructose units **significance**: renal function tests (used to test filtration rate & renal clearance value), injected and what you put in is what should come out (if not = problem w/ kidney) body can't digest but can absorb

Answer 21

made of special sugar called **N-acetyl-D-glucosamine** these sugar units joined by **β-1,4 glycosidic bonds** in **exoskeletons** of insects, crabs, shrimp, and other arthropods

Answer 22

intermediate in starch hydrolysis (starch breaks into this first) *has the same linkages as starch* **uses**: used in **wheat glue** and can be added to foods to help them stick together, used in pharmaceutical preparations to bind constituents of the pill, food preservative

Answer 23

**large** (high molecular weight), **highly branched** polysaccharides synthesized by **microorganisms** **linkages**: Mainly α-1→6, with some α-1→3 and α-1→4 **uses**: mostly for medical uses, blood volume expanders, maintain blood plasma volume, helps prevent blood clots, organ transplantation storage

Answer 24

**dextrose**: another name for glucose, used in medical drips **dextrin**: partially digested product of starch **dextran**: synthesized by microorganism, highly branched glucose polymer, used medically & in Pharma

Answer 25

**GAGs** = glycosaminoglycans long, unbranched, heteropolysaccharide chains that are composed of repeating disaccharide units (1 acidic sugar- 1 amino sugar) - *synthesized in body from simple sugars*

Answer 26

1. key components of **ECM** 2. Contribute to the **turgor** of various tissues: help w/ water retention too 3. Act as **sieves** in ECM: allow smaller molecules to pass through, prohibiting larger ones 4. Facilitate **cell migration**, act as **shock absorber** at joints 5. Maintenance of **compressibility of cartilage**: allow cartilage to compress & rebound, helping it absorb shock 6. Have a structural role in **sclera & in corneal transparency**: white part of eye 7. Act as anticoagulant 8. Formation of cell membrane and **synaptic vesicles**

Answer 27

sulphate free & sulphate containing **sulphate free** → hyaluronic acid (*only 1*) **sulphate containing** → - chondrotin sulphate - dermatan sulphate - keratan sulphate - heparin - heparan sulphate *all have sulphate in the name except for 1*

Answer 28

linkages b/w disaccharides is **beta 1-4** but b/w the units themselves is **beta 1-3** **found in**: synovial fluid of joints, umbilical cord, loose connective tissue, & cartilage

Answer 29

1. Key component of synovial fluid which **lubricates joints** → helps maintain flexibility & strength by retaining water and keeping cartilage strong 2. stimulates production of synovial fluid 3. injectable **treatment for rheumatoid & osteoarthritis** 4. helps **deliver nutrients & removal of waste** from cartilage cells (they don't have blood supply) 5. Deficiency causes brittle and deteriorating joints 6. Helps in **wound healing** by promoting cell migration and increasing moisture at site of injury 7. **Cosmetic products** - injectable fillers that lessen appearance of lines, sagging, and depression of skin

Answer 30

present intracellularly (inside the cell)

Answer 31

**Linkage**: alpha 1→ 4, disaccharide units of glucoronic or iduronic acid & glucosamine **location**: found in mast cells lining arterial vasculature of liver, skin, spleen, lungs, and monocytes (*not an LO tho*) **function**: serves as anticoagulant

Answer 32

**function**: regulates biological activities including angiogenesis (new blood vessel formation), blood coagulation, and tumor metastasis **linkage**: same as heparin (alpha 1-4) **location**: basement membranes, component of cell surfaces

Answer 33

**heparan sulfate** has a greater proportion of GliA (glucuronic acid), is less sulfated than heparins, and is present extracellularly

Answer 34

*"chondra" stands for cartilage* **location**: ground substance of connective tissues, widely distributed in cartilage, bones, tendons, cornea, and skin **linkage**: beta 1,3 and beta-1,4 **structure**: galactosamine sulphate & glucuronic acid (GlcA) **functions**: provides strength & elasticity, maintains water retention, important for joint health, structural support

Answer 35

**structure/linkage**: repeating units of iduronic acid & N-acetylgalactosamine - linked by **β-1,3** bonds **location**: largely in skin (*derma for skin*), blood vessels, heart valves **functions**: structural support, resists mechanical stress, role in wound healing

Answer 36

linkages: **β-1,3** & **β-1,4** **components**: galactose & N-acetylglucosamine different from other GAGs bc **no uronic acid** **location**: tendons, loose connective tissues, cornea

Answer 37

**glycoproteins**: proteins that have *oligosaccharides* (sugar chains) covalently attached to them sugars attached through 2 types of glycolysation: 1. **co-translational glycosylation**: happens while protein is still being made (during translation on the ribosome) 2. **post-transational glycosylation**: happens AFTER protein is fully made, during further processing inside ER or Golgi

Answer 38

what they do in the body *examples on slides*: **immunoglobin (IgG)**: only 4% of it is carb b/c its main job is fighting infections so needs more protein structure **mucin**: unto 80% carbs! sugars make it slippery, sticky, and protective -- perfect for lining & protecting surfaces

Answer 39

can be divided into 2 major classes based on **nature of linkage** b/w protein (polypeptide) & sugar (oligosaccharides) chains **O-linked**: sugar (glycan) attached to O atom of amino acids **serine or threonine** **N-linked**: sugar (glycan) attached to N atom of **asparagine**

Answer 40

1. Almost all proteins found in **plasma** (*liquid part of blood*) are glycoproteins except **albunim** 2. Components of ECM: hold tissues together - glycoproteins in **collagen** help with tissue strength & flexibility 3. **Protective biological lubricants**: muffins in the gastrointestinal and urogenital tracts 4. **Immune response**: antibodies (IgG, IgA) are glycoproteins 5. **Cell-surface recognition**: help cells recognize and interact w/ other cells, hormones, viruses 6. mane **Enzymes** are glycoproteins: oxidoreductases, transferases, hydrolases

Answer 41

huge molecules made **mostly of carbohydrate** (GAGs) and a **little protein**. - help build & support tissues in body—especially in cartilage, skin, and the extracellular matrix (ECM) **structure**: made of a core protein + long chains of GAGs attached to it - are **negatively charged** b/c of sulfate & carboxyl groups in GAGs - look like a bottle brush under microscope

carbohydrates (b1- foundation) Flashcards

(65 cards)