USMDO prep

What are macromolecules?

Large complex molecules typically composed of thousands of atoms, including proteins, nucleic acids, carbohydrates, and lipids, which are essential for the structure and function of cells.

What are the structures of the cell?

Include organelles such as the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and the cytoskeleton, each performing specific functions vital for cellular operation.

Nucleus

Control center containing DNA that directs all of the cell's daily activities.

Mitochondria

Cellular powerhouses that convert food into usable ATP energy through cellular respiration.

Endoplasmic Reticulum

Protein and lipid factory and highway that builds and moves materials.

Golgi Apparatus

Shipping center that sorts, modifies, and packages proteins for delivery.

Lysosomes

Clean-up crews filled with digestive enzymes to break down waste and old parts.

Cytoskeleton

Internal network of protein fibers providing shape, strength, and movement tracks.

Ribosomes

Tiny structures that make proteins by following instructions from the nucleus.

What is the cell membrane?

A barrier that surrounds the cell, composed of a lipid bilayer with embedded proteins, controlling the movement of substances in and out of the cell.

What are passive and active transport?

Passive transport is the movement of substances across a cell membrane without the use of energy, while active transport requires energy to move substances against their concentration gradient.

What is metabolism?

A set of life-sustaining chemical reactions in organisms that convert food into energy, encompassing both catabolic (breaking down) and anabolic (building up) processes.

What is cellular respiration?

The metabolic process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.

What is cell signaling?

The communication process between cells that involves the release and reception of signaling molecules, enabling cells to respond to changes in their environment.

What is mitosis?

The process of cell division that results in two identical daughter cells, allowing for growth and repair of tissues.

What is meiosis?

A specialized form of cell division that reduces the chromosome number by half, producing gametes (sperm and eggs) for sexual reproduction.

Genetic Identity

Mitosis makes identical clones, while meiosis creates genetically diverse cells.

Cell Count

Mitosis creates two cells, whereas meiosis yields four cells.

Ploidy Change

Mitosis maintains diploid cells (2n), while meiosis cuts them to haploid cells (n).

Divisions

Mitosis has one division, but meiosis goes through two divisions.

Synapsis

Process where homologous chromosomes pair up tightly during prophase I of meiosis.

Tetrad

Group of four chromatids formed when homologous chromosomes pair together.

Crossing Over

Exchange of DNA pieces between homologous chromosomes to mix genetic traits.

Chiasmata

Physical X-shaped crossover points where chromosomes trade genetic material.

Chromatid Separation

Occurs during mitosis anaphase and meiosis anaphase II when single strands separate.

Metaphase Plate

Mitosis aligns individual chromosomes, while meiosis I aligns chromosome pairs.

What is Mendelian genetics?

Mendelian genetics is the study of how traits are inherited through the segregation and independent assortment of alleles, based on the work of Gregor Mendel.

What are chromosomes?

Chromosomes are long strands of DNA tightly coiled around proteins, containing the genetic information necessary for the growth, development, and functioning of an organism.

What is DNA?

DNA (deoxyribonucleic acid) is the molecule that contains the genetic instructions for the development and function of living organisms.

What is replication in the context of DNA?

Replication is the process through which DNA makes a copy of itself, ensuring that each new cell receives an accurate copy of the genetic information.

Helicase

Unwinds the DNA helix and splits the two matching strands apart.

Topoisomerase

Relieves twisting tension ahead of the replication fork so DNA does not tangle.

Primase

Places a short RNA primer to give DNA polymerase a starting point.

DNA Polymerase III

Main enzyme that adds new nucleotides to build the new DNA strand.

Synthesis Direction

Always builds the new DNA strand in the 5' to 3' direction.

DNA Polymerase I

Removes RNA primers and replaces them with actual DNA pieces.

DNA Ligase

Glues DNA fragments together by making covalent bonds in the sugar-phosphate backbone.

Okazaki Fragments

Short DNA pieces built pieces-at-a-time on the backward-facing lagging strand.

Leading vs. Lagging

Leading strand builds continuously forward, while the lagging strand builds discontinuously backward.

SSB Proteins

Bind to single strands to keep them from snapping back together.

What is transcription?

Transcription is the process of synthesizing RNA from a DNA template, allowing the genetic information to be carried from the nucleus to the cytoplasm.

What is translation?

Translation is the process by which the information in mRNA is used to synthesize proteins at the ribosomes in the cytoplasm.

What is gene regulation?

Gene regulation is the control of the timing and amount of gene expression, ensuring that genes are transcribed and translated at the right times and in the right amounts.

What are viruses?

Viruses are microscopic infectious agents that can only replicate inside the living cells of an organism, consisting of genetic material encased in a protein coat.

What are bacteria?

Bacteria are single-celled microorganisms that can exist independently or as parasites, classified by their shapes and their ability to cause diseases in humans.

What is biotechnology?

Biotechnology is the manipulation of living organisms or their components to develop products and technologies that improve the quality of life.

What is cell death?

Cell death is a natural process in which cells undergo a series of changes leading to their destruction, which can occur through apoptosis (programmed cell death) or necrosis (uncontrolled death).

What is cancer?

Cancer is a disease characterized by the uncontrolled division and growth of abnormal cells, which can invade and damage surrounding tissues.

What are stem cells?

Stem cells are undifferentiated cells capable of giving rise to various cell types and are involved in growth, development, and tissue repair.

cAMP

Common second messenger that carries a signal from the cell surface inside.

IP3 and DAG

Secondary messengers that trigger calcium release and activate internal enzymes.

Calcium Ions

Signal molecules stored in the ER released to spark cell actions.