chapt 2 notes

monounsaturated

A fatty acid has one double bond.

polyunsaturated

A fatty acid has two or more double bonds.

What is a trans fat?

A fat that has been artificially/chemically altered and can be damaging to the body because it is difficult to break down.

What are eicosanoids made from?

Fatty acids.

What are prostaglandins?

Eicosanoids made from fatty acids that are released by damaged tissue and can cause pain; they also help trigger labor contractions.

glyceride

A lipid consisting of fatty acid(s) attached to a glycerol molecule.

monoglyceride

Glycerol attached to one fatty acid

diglyceride

Glycerol attached to two fatty acids

triglyceride

Glycerol attached to three fatty acids; it is the body's main form of stored fat.

Where are triglycerides stored

In adipose (fat) cells.

What are the four major functions of triglycerides?

Energy storage, insulation, protection of organs, and absorption of fat-soluble vitamins.

What are the four fat-soluble vitamins?

A, D, E, and K.

What process breaks down triglycerides for energy?

Hydrolysis.

What are steroids?

Large lipids that include cholesterol, estrogen, and testosterone.

What are some functions of steroids in the body?

Cell membrane repair, production of sex hormones, regulation of metabolism, and production of bile salts.

Where is cholesterol produced in the body?

The liver.

What are phospholipids made of?

A phosphate head and two fatty acid tails.

What are glycolipids made of?

A carbohydrate head and two fatty acid tails.

What do the fatty acid tails of phospholipids and glycolipids do around water?

They hate/avoid water (they are hydrophobic).

What is the function of the lymphatic system in fat digestion?

It absorbs and transports fats because large fat particles cannot directly enter the bloodstream easily.

What determines which protein is produced?

The sequence of amino acids.

What four groups are attached to the central carbon of every amino acid?

A carboxyl group, amino group, hydrogen atom, and R group (side chain).

What determines which amino acid it is?

Its R group (side chain).

How many different amino acids are used in the human body?

20

What type of bond holds amino acids together?

A peptide bond, which is a covalent bond.

What is a dipeptide?

Two amino acids joined together.

What is a polypeptide?

A chain of three or more amino acids linked together.

What determines a protein's function?

Its shape.

What is the primary structure of a protein?

he linear sequence of amino acids.

What are the two possible forms of secondary protein structure?

Alpha helices and beta-pleated sheets.

What characterizes tertiary protein structure?

Interactions between amino acids cause the polypeptide to take on a three-dimensional shape.

What is quaternary protein structure?

When two or more protein chains bind together to form a functional protein.

How can a mutation in one amino acid affect a protein?

It can change the protein's shape and therefore alter its function.

Q: What is an example of a disease caused by an altered protein structure?

Sickle cell anemia, in which an altered hemoglobin protein does not function normally.

How many oxygen molecules can one hemoglobin molecule carry?

Up to 4 oxygen (O₂) molecules

What is the approximate number of hemoglobin molecules in one red blood cell?

About 240 million.

Approximately how many red blood cells are in the human body?

About 25 trillion.

What are the two types of nucleic acids?

DNA and RNA.

What elements make up nucleic acids?

Carbon, hydrogen, oxygen, nitrogen, and phosphorus

What are nucleic acids made of?

Nucleotides.

What are the three components of a nucleotide?

A 5-carbon sugar, a phosphate group, and a nitrogen-containing base.

What are the purine bases?

Adenine (A) and guanine (G).

What are the pyrimidine bases?

Cytosine (C), thymine (T), and uracil (U).

Which base pairs with guanine?

c

What does the "D" in DNA stand for?

Deoxyribose.

What does the "R" in RNA stand for?

Ribose.

What type of sugar does DNA contain?

Deoxyribose.

What type of sugar does RNA contain?

Ribose.

What are the three types of RNA?

Messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

Where does DNA remain in the cell?

Inside the nucleus.

What does RNA do after being copied from DNA?

RNA can leave the nucleus and carry the genetic instructions to cellular machinery that makes proteins.

How many chromosomes does a typical human cell have?

46 chromosomes, 23 from each parent.

How is a high-energy molecule made?

Through phosphorylation, the addition of a phosphate group.

How do cells release energy from high-energy compounds?

By breaking a covalent bond between a phosphate group and an organic molecule.

What is ATP?

Adenosine triphosphate, the cell's stored/potential energy molecule.

What helps break ATP's bonds when energy is needed?

An enzyme.

What is an element?

A pure substance composed of atoms of only one kind.

What is the difference between a single and double covalent bond?

A single bond involves sharing one pair of electrons; a double bond involves sharing two pairs.

What is alkalosis?

A condition in which the blood becomes too alkaline/basic.

What is acidosis?

A condition in which body fluids become too acidic, causing a lower-than-normal blood pH.

What are electrolytes?

Electrically charged minerals that are important for hydration, nerve and muscle function, and heart rhythm.

What are common electrolytes?

Sodium, potassium, calcium, magnesium, chloride, and phosphate.

What is diffusion?

The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Does diffusion require cellular energy?

No. It is a passive process.

What is osmosis?

The passive movement of water across a selectively permeable membrane toward the side with the higher solute concentration.

Does osmosis require energy?

No. It is a passive process.

What does isotonic mean?

Two solutions have equal solute concentrations, resulting in no net movement of water across the membrane.