Structure and Function of Large Biological Molecules and Cell Overview

Practice flashcards covering the structure and function of biological macromolecules, cell organelles, membrane transport, and tonicity.

What are the four classes of macromolecules essential for life?

Carbohydrates, Proteins, Nucleic Acids, and Lipids

Which metabolic process involves building polymers from monomers?

Condensation Reaction (also known as Dehydration Reaction)

What is the monomer of a nucleic acid?

Nucleotide

Name the three components that make up a nucleotide.

Pentose sugar, phosphate group, and nitrogenous base

How are nucleotides linked together in a polynucleotide strand?

Phosphodiester bonds

Which nitrogenous bases are classified as double-ringed purines?

Adenine (A) and Guanine (G)

What are the base pairing rules for DNA?

Cytosine (C) binds with Guanine (G) and Adenine (A) binds with Thymine (T)

What are the base pairing rules for RNA?

Cytosine (C) binds with Guanine (G) and Adenine (A) binds with Uracil (U)

How is the structure of a DNA double helix described regarding the orientation of its strands?

Anti-parallel and complementary

What property is shared by all lipids?

They are hydrophobic and do not mix with water

Which lipid consists of one glycerol attached to three fatty acid chains?

Triglyceride (or Triacylglycerol)

What is the primary difference between saturated and unsaturated fatty acids?

Saturated fatty acids have only single bonds between carbon atoms and are solid at room temperature, while unsaturated fatty acids have one or more double bonds (leading to kinks) and are liquid at room temperature

Why are phospholipids described as amphipathic?

Because they contain both a hydrophilic head (glycerol, phosphate, and a charged molecule) and hydrophobic tails (two fatty acid chains)

What are the four levels of protein structure?

Primary ($1^o$), Secondary ($2^o$), Tertiary ($3^o$), and Quaternary ($4^o$)

Which bonds hold the primary structure of a protein together?

Peptide bonds

What are the two common shapes found in the secondary structure of a protein?

$\alpha$ helix and $\beta$ pleats

What occurs when a protein denatures?

The protein loses its unique 3D shape (unravelling) due to extreme environmental conditions like pH, salt concentration, or temperature, becoming nonfunctional

Distinguish between integral and peripheral membrane proteins.

Integral proteins extend into the plasma membrane (some are transmembrane), while peripheral proteins are bound to only one side of the membrane surface

Define facilitated diffusion.

A type of passive transport where polar molecules, ions, or large molecules cross the membrane through specific transport proteins along their concentration gradient without requiring energy

How does the Sodium-Potassium Pump operate during active transport?

It uses ATP to pump $3\,Na^+$ ions out of the cell and $2\,K^+$ ions into the cell, both against their concentration gradients

What is the function of the nucleolus?

The production of ribosomes

Identify the primary functions of the Smooth Endoplasmic Reticulum (SER).

Production of lipids (fatty acids and steroids), detoxification of drugs and poisons, and storage for Calcium ions

Which organelle acts as the 'FedEx' or sorting center for the cell?

The Golgi Apparatus

What are the three components of the cytoskeleton in eukaryotes?

Microtubules (largest), intermediate filaments, and microfilaments (thinnest)

What term describes a solution with a higher solute concentration compared to the inside of a cell?

Hypertonic

What happens to a red blood cell placed in a hypotonic solution?

Water diffuses into the cell, causing it to swell and eventually lyse (burst)

Distinguish between phagocytosis and pinocytosis.

Phagocytosis is 'cell eating' where the cell engulfs large particles, while pinocytosis is 'cell drinking' where the cell absorbs drops of extracellular fluid

What byproduct is created by peroxisomes when they detoxify compounds?

Hydrogen peroxide ($H_2O_2$), which is then converted to water

What structures provide cytoplasmic channels between adjacent plant cells?

Plasmodesmata