Chemical Makeup of Cells (E1) Bio

The reactivity of an atom is dependent on what?

The outer shell (valence)

Ionic bond

When atoms exchange electrons to fill their valence shell, forming ions.

Covalent bond

Atoms can fill their valence shell by sharing electrons

Carbon

Biomolecules consist of mostly what?

Molecular Formula

Lists # of each atom

Structural Formula

Shows bonding pattern

Line-Angle Formula

Short-hand structural formula. Hydrogens bonded to carbon are not drawn

Ball-Stick Model

The visual bonding in 3D space

Nonpolar covalent bond

Shared pair of electrons that spend equal time together

Polar covalent bond

One atom pulls more force (non-equal sharing)

Electronegativity

Covalent bond polarity is dependent on differences in ____

Covalent bonds are a form of ___

Energy

What is Bond Energy?

The amount of energy needed to break a covalent bond. Measure of strength.

What is the bond energy and potential energy of a Nonpolar bond?

Lower bond energy, Higher potential energy (electrons are less stable)

What is the bond energy and potential energy of a polar bond?

Higher bond energy (more energy needed to break), Lower potential energy (electrons are more stable)

Non-polar C-H bonds

Cells capture energy from organic molecules that contain many ____ bonds. ___ = MORE POTENTIAL ENERGY

Hydrogen bond

Electrical attraction between a covalently bonded H atom and an electronegative atom

Hydrophobic interaction

Interaction of non-polar substances in the presence of polar substances (especially water)

van der Waals interaction

Interaction of electrons of non-polar substances (short & weak)

Polar Molecules are ____ : they dissolve in H2O because they can form hydrogen bonds with water

Hydrophilic

Nonpolar molecules are _____: they’re repelled by water because they cannot form hydrogen bonds with water

Hydrophobic

Ions are polar and dissolve in water through ___ interactions

Ion-dipole

Nonpolar molecules that cannot hydrogen bonds separate water through _______

Hydrophobic Exclusion

Hydrophobic molecules in water interact with each other through _____ interactions

Van der Waals

What are Hydroxyl properties?

Polar, forms hydrogen bonds with water.

What are Aldehyde properties?

Polar. C=O group is very reactive. Important in building molecules and in energy- releasing reactions.

What are Keto properties?

Polar. C==O group is important in carbohydrate and in energy reactions.

Monosaccharides contain what type of functional group?

Polar groups : Aldehyde, Ketone.

Monosaccharides form ___ structures in aqueous solutions

Cyclic

Alpha Orientation of Monosaccharides

H on top, OH (Hydroxl) on bottom

Beta Orientation in Monosaccharide

OH (Hydroxl) pointing up, H pointing down

How are disaccharides formed?

Monosaccharides linked by a condensation reaction

Glycosidic linkage (single oxygen bond)

A condensation reaction builds a ____ between monosaccharides

Disaccharides are broken down through ____ reactions

Hydrolysis

Different glycosidic linkages require different ____ for hydrolysis

Enzymes (ex. Sucrase, Lactase)

Monosaccharides can be linked together to form _____

Polysaccharides (starch, glycogen , cellulose)