Chapter 2 Water Flashcards
(86 cards)
What is the structure of a water molecule?
Consists of 2 hydrogen atoms and one oxygen atom joined by shared electrons (covalent bonds)
Shared negative hydrogen electrons are pulled towards the oxygen atom, making the molecule polar.
What charge do the hydrogen and oxygen atoms acquire in a water molecule?
Slightly negatively charged oxygen (δ-) and slightly positively charged hydrogen (δ+)
This occurs due to the unequal sharing of electrons.
How do hydrogen bonds form between water molecules?
Slight negatively charged oxygen atoms attract slightly positively charged hydrogen atoms in adjacent water molecules
This is a result of dipoles formed by electronegativity.
How much weaker are hydrogen bonds compared to covalent bonds?
20 times weaker
Hydrogen bonds are technically weak intermolecular forces, not actual bonds.
What is the significance of water’s high specific heat capacity?
It helps keep aquatic habitats thermally stable and stabilizes internal body temperature as the environment changes
SHC = energy required to raise the temperature of 1g of water by 1°C.
What is the biological importance of water being transparent?
Allows light to pass through, which is important for the light-dependent stage of photosynthesis
This transparency facilitates the photosynthetic process in aquatic environments.
What is meant by the high heat of latent evaporation of water?
Energy required to break hydrogen bonds between water molecules to convert water from liquid to gaseous state
Important for thermoregulation in mammals, such as cooling by sweating.
Why is cohesion important in water molecules?
It allows the formation of long continuous columns of water in xylem vessels during transpiration
Cohesion is the attraction between dipoles of adjacent water molecules forming hydrogen bonds.
What role does water play as a universal solvent?
Carries polar molecules and ions, dissolving them for transportation and facilitating biochemical reactions
Important for transporting ions, proteins, and waste products in biological systems.
What happens to water when it freezes?
H2O molecules are held further apart, causing density to decrease and allowing ice to float
This insulates water beneath the ice and provides habitats for some organisms.
What is adhesion in the context of water?
Hydrogen bonding allows water to stick to surfaces like the lining of xylem vessel walls and cellulose in cell walls
This aids in the movement of water in plants and reduces friction in various biological fluids.
What is the definition of biofluids?
Liquids within the body, including those secreted or excreted by the body
Examples include bile, semen, breast milk, and cerebrospinal fluid.
What is the process of forming tissue fluid?
Hydrostatic pressure gradient forces plasma fluid out of capillaries through fenestrations
This is an example of ultrafiltration.
What is lymph and how is it formed?
Fluid that drains excess tissue fluid back into the blood circulatory system via lymph vessels
Lymph is similar to tissue fluid but contains more leucocytes.
What are the main components of serum?
Plasma with clotting factors removed, including electrolytes, antibodies, hormones, and soluble proteins
Serum is used in blood typing and diagnostic testing.
What is the primary function of plasma?
Transports dissolved substances and provides body cells with water
Plasma accounts for ~50-60% of total blood volume.
What are the functions of carbohydrates in biofluids?
Structural, cell markers, energy source, energy store, and macromolecule synthesis
Functions summarized as “SCEEM.”
What is a condensation reaction?
Joining of two monomers by the removal of H2O to form a new covalent bond
This process is essential for forming disaccharides.
What is the structure of glycogen?
A branched molecule formed from many α-glucose molecules via glycogenesis
It is compact and insoluble, allowing for efficient storage.
What is the role of serum albumin?
Regulates osmotic balance and pH buffering
It also aids in calcium transport.
What are the two main categories of biofluids?
Intracellular and extracellular
Intracellular includes cytosol; extracellular includes plasma and tissue fluid.
What is the primary characteristic of a polysaccharide?
Made of many monosaccharide molecules joined by glycosidic bonds
Polysaccharides are complex carbohydrates formed by the polymerization of monosaccharides.
What are the two polysaccharides that form starch?
- Amylose
- Amylopectin
Where is starch primarily located in plants?
Starch grains inside plant cells, seeds, and storage organs e.g. tubers
