Food tests and heart biology

Test for Starch

Reagent used: Iodine solution

Method: Add a few drops of iodine solution to the food sample.

Positive Result: Blue-black colour

Test for glucose

Reagent Used: Benedict’s solution

Method: Add Benedict’s solution to the food sample and heat in a water bath at 80°C for 5 minutes.

Positive Result: Colour change from blue—>brick-red (depending on sugar concentration).

Test for Protein

Reagent Used: Biuret solution (a mixture of sodium hydroxide and copper(II) sulfate)

Method: Add Biuret solution to the food sample.

Positive Result: Color changes from blue to purple/lilac

Test for Lipids

Reagent Used: Ethanol and water

Method:

1. Add ethanol to the food sample and shake well.

2. Pour the mixture into water.

Positive Result: A milky-white emulsion

Function of blood vessels in heart

Pulmonary means anything relating to the lungs.

Arteries

• narrow lumen

• withstands high pressure blood flow

• thick, elastic walls made of muscle

• NO VALVES

• typically carry oxygenated blood

Veins

• walls are thinner than in arteries as the blood is at a lower pressure

• low pressure hinders blood flow, so they have a wider cross-section through which blood can flow

• HAVE VALVES TO PREVENT BACKFLOW OF BLOOD

• generally carry de-oxygenated blood

Heart chambers and function

• Blood enters the heart via the atria.

• Once filled with blood, the atria contract, forcing blood down into the ventricles below.

• When the ventricles contract, they force blood to exit the heart.

• A group of cells in the right atrium act as a pacemaker, controlling the pumping of the heart.

key difference between eu- and prokaryotic cells

eukaryotic HAVE NUCLEUS

prokaryotic DO NOT HAVE NUCLEUS

prokaryotic cells

• Prokaryotic cells do NOT contain mitochondria (where respiration takes place) or chloroplasts (where photosynthesis takes place).

• Prokaryotic cells do not have a nucleus (where DNA is stored).

• Instead, most of their genetic material is stored in a single DNA loop in the cytoplasm (watery jelly that fills the cell).

• Some prokaryotic cells contain small rings of DNA called plasmids.

• These plasmids can replicate and move between cells so that genetic information can be shared.

Eukaryotic cells

contain cell membrane, cytoplasm and NUCLEUS

animal cell

• The cell membrane separates the interior (inside) of the cell from the environment outside.

• This membrane is selectively permeable. This means that it has control over which substances enter and exit the cell.

• The nucleus contains chromosomes (which contain the cell's genetic material).

• Ribosomes are responsible for making proteins.

• Mitochondria is where aerobic respiration takes place.

• Aerobic respiration is a process which uses glucose and oxygen to release energy.

• Cytoplasm is a jelly-like fluid that fills the cell.

• It is where most of the cell’s chemical reactions take place.

• some include:

• Skin Cells

• Muscle Cells

• Blood Cells

• Nerve Cells

• Fat Cells

plant cell

• A permanent vacuole is a fluid-filled sac that stores water.

• It is enclosed in a membrane (a wall that substances can pass through).

• It can make up as much as 90% of a plant cell’s volume.

• Chloroplasts contain chlorophyll needed for photosynthesis.

• The cell wall surrounds the cell and is made of cellulose.

• The cell wall increases the structural strength of the cell.

differences between animal and plant cell

• Many plant cells can differentiate throughout their lives.

• This means that plants are always able to create new tissues.

• Most animal cells differentiate early on in their development.

• In mature animals, cells mostly divide (one cell splits to create two cells) to replace cells and repair tissues that are already present.

• New tissues are rarely created by cell differentiation.

bacterial cells

cytoplasm, plasmids, can have flagella (whip-like structures used for movement), membrane and a cell wall, which provides structure.

layers of a vascular plant cell

xylem and phloem cell functions

• xylem’s main job is to transport water and minerals from the roots to the leaf

• phloem's main function is to distribute nutrients, such as sugars and organic compounds, produced in photosynthetic tissues to various parts of the plant.

Diffusion

Substances move from a high to a low concentration down a concentration gradient

Carbon dioxide, oxygen, water, food substances, wastes, eg urea are transported

no energy required

Osmosis

Water moves from a high to a low concentration across a partially permeable membrane and down a concentration gradient

no energy required

Active transport

Substances move against a concentration gradient

Mineral ions into plant roots, glucose from the gut into intestinal cells, from where it moves into the blood are transported

energy is required and it is produced during respiration