Biology CLEP

CLEP Website: https://clep.collegeboard.org/clep-exams/biology

What type of bond joins oxygen to hydrogen within a single water molecule?

polar covalent bond

Why is the bond between oxygen and hydrogen within a single water molecule a polar covalent bond?

The oxygen atom has a higher electronegativity than the hydrogen atoms, causing the shared electrons to be pulled closer to the oxygen, resulting in a partial negative charge on the oxygen and a partial positive charge on each hydrogen. This is an unequal sharing of electrons.

Polar Covalent Bond

A type of chemical bond where electrons are shared unequally between two atoms due to a difference in their electronegativity, resulting in one atom having a slightly positive charge and the other having a slightly negative charge. One atom pulls the shared electrons closer to itself more strongly than the other atom does

Nonpolar covalent bond

A type of chemical bond where two atoms share electrons equally, meaning there is no uneven distribution of electrical charge between the atoms involved, typically occurring when the atoms have similar electronegativity values; essentially, both atoms “pull” on the shared electrons with the same force. Key points: EQUAL ELECTRON SHARING and SIMILAR ELECTRONEGATIVITY

Peptide bond

A covalent bond that links amino acids together to form a protein

Ionic Bond

Results from the attraction between oppositely charged ions

Hydrogen Bond

A dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom. Results from the attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as N, O, or F and another electronegative atom.

Dipole-Dipole

Polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule. Weaker than ionic or covalent but stronger than London and ion-ion. Not very effective in the gaseous state because molecules are far apart.

The smallest unit of matter that has the properties of a particular element is a/n

atom

A carbohydrate monomer is called a/n

monosaccharide

Carbosaccharide

Organic compounds that contain carbon, hydrogen and oxygen. Main source of energy for the body (controls blood glucose and insulin metabolism) and structural components in plants (glucose chains in amylose and amylopectin)

Monosaccharide

The simplest form of carbohydrates, which are simple sugars. Examples include glucose and fructose.

What are glucose and fructose?

Monosaccharides

Monohydrate

A chemical term for a substance that contains one molecule of water for each molecule of combining compound.

What substances are monohydrates found in?

creatine and dextrose (sweetener, energy source and bulking agent)

What are monohydrates used for?

To improve muscular endurance, recovery and energy levels

How are monohydrates made?

They are made outside the body from sarcosine and cyanamide. Then these compounds are heated and pressurized in a reactor to form creatine crystals.

Amino Acide

molecules that combine to form proteins. The result of proteins being digested or broken down

Polypeptide

A chain of amino acids that are linked together by peptide bonds. Essential for the structure and function of cells and tissues.

Which of the following RNA sequences would bond to this DNA strand?: AATAG

UUAUC

DNA and RNA base pairing

• Adenine (A) always pairs with thymine (T) in DNA and uracil in DNA

• Guanine (G) always pairs with cytosine (C) in both DNA and RNA

• The key difference is that DNA uses thymine while RNA uses uracil as its complementary base to adenine

DNA base pairs

Adenine (A) with Thymine (T), Guanine (G) with Cytosine (C)

RNA base pairs

Adenine (A) with Uracil (U), Guanine (G) with Cytosine

Importance of DNA and RNA base pairs

This complimentary base pairing is crucial for maintaining the structure of DNA and RNA molecules, as well as for processes like transcription (copying DNA into RNA) and translation (converting RNA into proteins)

Transcription

The process of creating an RNA molecule from a DNA template

AAUAG

TTATC

UUAUC

AATAG

TTATG

AAUAC

AATAG

UUAUC

A covalent bond occurs when

two atoms share electrons between them, effectively filling their outer electron shells and achieving stability by forming electron pairs

Two atoms are attracted to each other

chemical bond

One atom donates an electron to another

Ionic bond

Two atoms share an electron

Covalent bond

One atom steals an electron from another

Ionic bond

What property of water allows life to exist in a lake when temperature is below freezing?

Solid ice has a lower density compared to its liquid state. The ice floats on water, creating an insulating layer on the surface and allowing aquatic life to survive in the liquid water below the ice.

The nearly universal nature of the genetic code supports the view that

all living organisms on Earth share a common ancestor

Structure and Function of Cell Organelles

• cell basics

• Cytoplasm and cell membrane

• Nucleus

• Ribosomes

• Endoplasmic Reticulum

• Golgi apparatus

• Mitochondria and chloroplasts

• Cytoskeleton Cell Wall

Properties of cell membranes

• membrane basics

• selective permeability

• transport basics

• passive transport

• active transport

Comparison of prokaryotic and eukaryotic cells

• cell basics

• prokaryotic cell characteristics

• eukaryotic cell characteristics

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