Protein, Carbohydrates, and Lipids BIO HL

These flashcards cover the major concepts from the lecture: carbohydrate and lipid chemistry, protein structure and function, metabolic reactions, molecular genetics, and basic research terminology.

Hydrocarbon chains (carbon bonded to hydrogen).

What element must an organic molecule contain to be considered organic?

Monosaccharide – glucose; Disaccharide – fructose (note: lecture mis-labels fructose but treats it as di-); Polysaccharide – starch or cellulose.

Name the three classes of carbohydrates and give one example of each.

Condensation (dehydration synthesis) reaction.

What type of reaction forms a glycosidic bond between monosaccharides?

Between the 1-carbon of one α-glucose and the 4-carbon of the next glucose.

Between which carbon atoms is an α-1,4 glycosidic bond formed in glucose?

The orientation of the –OH group on carbon-1 (up in β, down in α).

What structural change distinguishes β-glucose from α-glucose?

Simple lipids (triglycerides) – energy storage; Complex lipids (phospholipids) – membrane structure; Derived lipids (steroids/cholesterol) – signaling & membrane fluidity.

List the three types of lipids discussed and one key role for each.

MUFA – mono-unsaturated fatty acid with one C=C double bond; PUFA – poly-unsaturated fatty acid with more than one C=C double bond.

Define MUFA and PUFA.

Hydrogenation.

What industrial process adds hydrogen to break double bonds in fatty acids?

A cis C=C double bond.

What is the structural ‘kink’ in an unsaturated fatty acid chain caused by?

In cis fats, hydrogen atoms attached to the C=C are on the same side, causing a bend; in trans fats they are on opposite sides, producing a straight chain.

Explain the difference between cis and trans fats.

Fats are hydrophobic; they bind to proteins forming lipoproteins (e.g., HDL, LDL).

Why must fats combine with proteins to travel in blood, and what are these complexes called?

HDL – it removes excess cholesterol from tissues and transports it to the liver.

Which lipoprotein is considered ‘good’ and why?

Ester bond.

What type of bond links fatty acids to glycerol in a triglyceride?

Carbon, hydrogen, oxygen, and nitrogen (C, H, O, N).

State the elemental composition common to all proteins.

An amine group (–NH₂) and a carboxylic acid group (–COOH).

What functional groups are present in every amino acid?

Condensation reaction forming a peptide bond (–CONH–).

What type of reaction links two amino acids, and what bond is formed?

On ribosomes in the cytoplasm (or rough ER).

Where in the cell are proteins synthesized?

Structural – collagen (strength/support); Functional – insulin (hormonal regulation).

Differentiate structural vs. functional proteins with an example each.

Genome – the complete set of genes/DNA in an organism; Proteome – the complete set of proteins expressed by an organism.

Define genome and proteome.

Hemoglobin – transports O₂/CO₂; Immunoglobulin – antibodies for immune defense.

Give two examples of globular proteins and their functions.

An amino acid form in aqueous solution carrying both a positive (–NH₃⁺) and a negative (–COO⁻) charge simultaneously.

What is a zwitterion?

Non-polar, Polar uncharged, Polar positive (basic), Polar negative (acidic).

List the four categories of amino acid R-groups mentioned.

Transcription; occurs in the nucleus.

What term describes the conversion of DNA to mRNA, and where does it occur?

The process of decoding mRNA into an amino-acid sequence; occurs on ribosomes.

What is translation and where does it happen?

Three nucleotides; one codon specifies one amino acid.

How many nucleotides make up a codon, and what does one codon specify?

Metabolic pathway that builds polymers from monomers (e.g., glucose → starch).

Define anabolism and give one example.

Metabolic pathway that breaks polymers into monomers (e.g., starch → glucose).

Define catabolism and give one example.

Hydrolysis.

Which reaction type is characteristic of catabolism?

High temperature and extreme pH.

State two factors that cause protein denaturation.

The peptide bond.

Which bond is the strongest within a protein’s primary structure?

Disulfide bond (–S–S–).

What bond type provides additional stabilization in tertiary structure and is the second strongest listed?

Conjugated proteins contain prosthetic groups and multiple types of polypeptide chains; non-conjugated have only polypeptide(s) without prosthetic groups.

Differentiate conjugated vs. non-conjugated (simple) proteins.

Fibrous proteins are long, narrow, and insoluble; globular proteins are compact, spherical, and water-soluble.

Give one key physical difference between fibrous and globular proteins.

Subcutaneous and visceral adipose; functions include insulation, shock absorption, and long-term energy storage.

Name the two types of adipose tissue and one function of adipose overall.

They are amphipathic—having hydrophilic heads and hydrophobic tails.

What property makes phospholipids ideal for forming cell membranes?

IV – independent variable manipulated; DV – dependent variable measured; CV – controlled variable held constant; Confounding variable – uncontrolled factor that may affect the DV.

In research design, distinguish between IV, DV, CV, and a confounding variable.

? It is a chemical process that involves the breaking of bonds in molecules by the addition of water, often used to break down polymers into monomers.

What is hydrolysis