Carbohydrate - Wed10am TUT02 by

Adult daily requirments

gtur9418_2 — 2021-08-18 00:25:51 UTC

The average adult should consume 8700kJ per day. It is suggested that carbs 40-60% of an adults daily energy intake. This is equivalent to about 220-230g/day.

Functions

2021-08-18 00:26:21 UTC

-Used as the main source of energy throughout the body through Krebs cycle
-Most basic form of energy (glucose)
-The ease at which the body digests the various carbohydrates is indicated by the Glycaemic Index (low GI has slow release of energy whereas high GI gives an unsustained spike of energy)
-Can be stored in the body as glycogen and released when blood sugar glucose levels are low

The Glycemic Index

2021-08-18 00:29:52 UTC

The GI ranks carbohydrates on a scale from 1-100 according to the speech by which they are digested, and the extent to which they raise blood sugar levels after eating

Low GI <55
Moderate GI 56-69
High GI >70

What is the structure of carbohydrates?

vraj0740 — 2021-08-18 00:32:18 UTC

The general structure of carbohydrates is C(n)H(2n)O(n).
Based on this basic structure, the number of each molecule will put carbohydrates into 3 subtypes:
- monosaccharides (glucose)
- disaccharides (sucrose, lactose)
- polysaccharides (cellulose, starch)

As polysaccharides have long, complex saccharide chains, the glycosidic bonds tend to take longer to chemically break down. As monosaccharides are simple sugars, they can be absorbed much quicker and will give energy at a quicker rate.

Energy content

2021-08-18 00:32:22 UTC

- Most basic form of energy used by the body
- The energy value is 17 kJ/g (4.0 kcal/g) for carbohydrates
- Used in the Krebs Cycle for cells to produce energy

FACT

gtur9418_2 — 2021-08-18 00:38:06 UTC

Glucose is the brain main source of fuel, unless under circumstances of extreme starvation.

Misconceptions

2021-08-18 00:39:25 UTC

According to the Cooper Institute, there is little to no scientific evidence that a low carb diet leads to long term weight loss or health improvements

Misconception 2

2021-08-18 00:44:33 UTC

Carbs are not the enemy. While many people often think that carbs are largely problematic, many studies have found that people who eat large servings of grains have a lower risk of developing diabetes, and better blood pressure

Amylose vs Amylopectin

vraj0740 — 2021-08-18 00:44:59 UTC

Both these polysaccharide molecules are known as 'starches'. However, they both provide a different energy content in terms of how quickly energy can be absorbed and for what time period it can be absorbed.

Amylose -> As amylose has a straight-chain polymer, amylase enzymes have greater access and can provide energy much quicker.
Amylopectin -> As amylopectin has a branched-chain polymer, enzymes take much longer to access and break down the polysaccharide, hence making the energy last a lot longer for the body.