Biomolecules (DNA/RNA), Cell Organelles, Membrane Proteins, and Osmosis (Lecture Notes)

Flashcards covering DNA/RNA structure and function, nucleotides, organelles, membrane proteins, glycoproteins, and osmosis concepts.

What biomolecule is genetic material made of nucleotides and constitutes genes in chromosomes?

DNA (Deoxyribonucleic Acid); it transfers hereditary information from cell to cell and across generations.

In DNA, which bases pair with which?

Adenine pairs with thymine; guanine pairs with cytosine.

What is the appearance of DNA's structure?

A double helix—an appearance like a twisted ladder formed by base pairs on a sugar‑phosphate backbone.

What is RNA?

RNA (Ribonucleic Acid) is composed of four nucleotides (A, G, C, U), is single‑stranded, and has three types: mRNA, tRNA, and rRNA.

Name the three types of RNA and their roles.

Messenger RNA carries genetic instructions from DNA to the ribosome; Transfer RNA brings amino acids to the ribosome; Ribosomal RNA assembles amino acids into proteins.

Which base in RNA replaces thymine?

Uracil.

What is ATP and its role?

Adenosine triphosphate; provides energy for cellular processes by releasing energy from high‑energy phosphate bonds.

What is the sugar‑phosphate backbone?

The repeating sugar‑phosphate chain that forms the structural framework of DNA (and RNA) to which bases attach.

What do genes do?

Genes act as a molecular code instructing cells in the assembly of amino acids into proteins.

How does DNA transfer hereditary information?

DNA transfers hereditary information from cell to cell and generations via mitosis and meiosis.

What are the DNA base‑pairing rules?

A pairs with T; G pairs with C.

How is the DNA double helix described in the notes?

As a twisted ladder formed by base pairs along the sugar‑phosphate backbone.

What are nucleotides used to make up?

Nucleic acids (DNA and RNA), which constitute genetic material.

What is a glycoprotein?

A protein with a carbohydrate attached; found on the inner or outer surface of the lipid bilayer; involved in cell recognition.

What are the two main classes of membrane proteins?

Integral proteins (embedded in the membrane) and Peripheral proteins (attached to the surface).

Give an example of a function of peripheral proteins on intestinal cells.

They can act as digestive enzymes on the cell surface to break down substances passing into the bloodstream.

Name two organelles commonly depicted in a prototypical animal cell diagram.

Nucleus and Mitochondria (others include ribosomes, rough ER, Golgi, etc.).

What is osmosis?

Movement of water across a semipermeable membrane.

What do iso-, hypo-, and hyper- prefixes mean in osmosis context?

Iso = same; Hypo = lower solute concentration; Hyper = higher solute concentration.

What happens to water when there is a solute imbalance across cell membranes?

Water moves to balance solute concentrations, which can affect cells (e.g., blood cells) if imbalances occur.

What are the three osmosis solution types described?

Hypertonic, isotonic, and hypotonic.

What are the four nucleotides found in DNA?

Adenine, thymine, cytosine, and guanine.

What are the four nucleotides found in RNA?

Adenine, uracil, cytosine, and guanine.