Biology: Digestion and absorption

From exam question paper

what is the positive result for the iodine test

Blue black

The term for enzymes "breaking down"substrates

Hydrolyzed/digested

The catalytic activity of Lipase occurs solely in the

Small intestine

Emulsify?

To breakdown fats into smaller fatty droplets

Purpose of the villi

To increase surface area for absorption. It has a size of 0.5 to 1.0mm long

Where is microvilli found

On the epithelial cells of the Villi it has a size of 30 to 100um)

what is x AND y

X is the blood capillary and circulatory system

Y is the Lymphatic system

Peristalisis

The process by which food is pushed along the oesophagus and small intestine

Describe one property that makes visking tube or dialysis tubing good for experiments

Visking tubes/ Dialysis tubing are partially permeable so small molecules can pass through

Why will the test be negative of the outer solution( distilled water)

This is because starch has to be hydrolysed into glucose before it is able to leave the tube. Starch will not be present in distilled water. Glucose is a smaller molecule than starch, so it cannot pass through the dialysis tubing while starch remains inside.

name a biochemical test for the products present in the water surrounding the viking tube

Benedicts test, as glucose will be present as starch is also hydrolysed into glucose

Atheroma

Lead to blockage in the coronary arteries.

Pancreatitis is a mdical condition that can lead to the pancreatic duct becoming blocked. It can also cause protein digesting enzymes to be released into the bloodstream. Why could this be harmful

The individual could digest their own proteins for example antibodies could be digested

Describe the role tat enzymes play in the digetsion and breakdown of amylase

The enzyme amylase

Breaks starch down into maltose

The enzyme maltose

breaks down maltase into glucose

Both enzymes break the glycosidic bonds

during hydrolysis reactions

Will a biuret test for amylase be positive

Yes, Amylase is an enzyme and therefore a protein.

Bile salts bind to fat droplets and break them down into smaller fat droplets. Explain how this process makes lipid digestion more efficient

Smaller droplets increases surface area. More surface area for lipase to act on

Why is mitochondria needed in the epithelial cell

Mitochondria carries out aerobic respiration produces ATP for active transport

How does the microvill being damageed affect the concentration of amino acids in the blood

Reduces surface area because Microvilli is damaged, so fewer carrier proteins, so less absorption of amino acid or fewer membrane bound dipeptidase to hydrolyze the proteins

The mechanism of amino acid leaving the epitheleal cell and explain why

Facilitated diffusion because amino acids are polar molecules

What does standard deviation represent

spread of data

What can affect the rate of digestion

size mass and gender can affect digestion even though all individuals are treated the same

explain why maltase catalyses only the maltase hydrolysis reaction

maltase is an enzyme and enyzmes are specific. because of this the active active is only complementary to maltase maltase will only bind to maltose forming enzyme substrate complexes.

Describe how proteins are digested in the human gyt

1. hydrolysis of peptide bonds

2. endopeptidase break polypeptides into smaller peptide chains

3. exopeptidases remove terminal amino acids

4. dipeptidase hydrolyse dipepetides into single amino acids

What reducing sugar would you expect to be produced during chewing of starch?

maltose because salivary amylase breaks starch down into maltose