AP Bio Unit 4 Complete Student Notes Flashcards

Essential for multicellular organisms, achieved mainly through chemical means or protein contact between cells.

Involves physical contact between cells or organisms. Normally through the binding of specific membrane proteins.

Cells near each other communicate through chemical messengers.

Signaling between cells far apart or different organisms. Normally occurs through hormones.

Cell signaling where a cell responds to signaling molecules it produces itself, affecting its own activity.

In biology, a type of cell communication where signaling molecules act on nearby target cells. The signaling molecules don't travel long distances.

Communication between cells using hormones released into the bloodstream to target distant cells with specific receptors.

Steps of cell signaling process.Occurs after contact between the ligand and the protein receptor occurs. Normally results in amplification of a certain reaction.

Also known as intracellular receptors, are located in the cytoplasm and respond to hydrophobic ligands. These receptors bind to proteins that regulate mRNA synthesis, affecting gene expression by binding to DNA and initiating transcription directly.

Also known as transmembrane receptors, they are integral proteins on cell membranes that bind external ligands. They facilitate signal transduction, converting extracellular signals to intracellular ones. These receptors are specific to cell types and have three main components: ligand-binding domain, membrane-spanning region, and intracellular domain. They play a crucial role in signaling in multicellular organisms and fall into three categories: ion channel-linked, G-protein-linked, and enzyme-linked receptors.

These bind ligands, opening a channel for specific ions to pass through the membrane. They have hydrophobic amino acids in the membrane-spanning region and hydrophilic amino acids inside the channel, allowing ions like sodium, calcium, magnesium, and hydrogen to pass through upon ligand binding.

G-protein-linked receptors bind ligands, activating G-proteins that interact with ion channels or enzymes. They have seven transmembrane domains and unique extracellular domains. Signaling involves G-protein activation by ligand binding, GTP exchange, and subsequent deactivation.

These are cell-surface receptors with intracellular domains associated with enzymes. They transmit signals upon ligand binding, activating enzymes that trigger cellular responses. An example is the tyrosine kinase receptor, which phosphorylates tyrosine molecules to propagate signals.

Mechanisms that regulate processes based on output.

Overview of stages in cell division.

The cell cycle consists of interphase (G1, S, G2) and mitotic phase (mitosis, cytokinesis). In mitosis, the cell divides its nucleus into two genetically identical daughter nuclei. It includes prophase (chromosomes condense), metaphase (chromosomes align at the metaphase plate), anaphase (sister chromatids separate and move to opposite poles), and telophase (chromosomes decondense). Cytokinesis follows, dividing the cytoplasm to form two daughter cells.

Cancer normally mutates something that would normally stop cell division. This causes unhindered cell division, which in turn leads to tumor and cancer growth.

Signaling molecules that control cell differentiation and tissue patterning during development by forming concentration gradients.

A communication system where bacteria release signaling molecules to coordinate group behaviors based on population density.

Chemical messengers released into the bloodstream to target specific cells.

Chemicals impacting behavior or physiology outside the secreting individual's body.

Lipid-based hormones that can pass through cell membranes to affect gene expression.

A signaling molecule that binds to a receptor protein on the cell membrane or inside the cell, causing a conformational change in the receptor to initiate a signal transduction pathway.

The initial step in cell signaling where a signaling molecule binds to a receptor, leading to a conformational change in the receptor and the transduction of the signal into the cell.

The process in cell signaling where a multi-step pathway transmits and amplifies a signal through the addition or removal of phosphate groups, often involving protein kinases and phosphatases.

The cellular action or regulation initiated by a signal transduction pathway, which can include ion channel opening, substance breakdown, gene expression, gene regulation, or cell growth/reproduction.

A cell surface receptor that initiates cell signaling pathways by phosphorylating tyrosine residues on target proteins.

A regulatory mechanism in biology where the product of a reaction leads to a decrease in that reaction, helping maintain stability or homeostasis by reversing changes away from a set point.

A regulatory mechanism where the product of a reaction leads to an increase in that reaction, amplifying effects and moving a system further from equilibrium, often occurring when rapid responses are needed.

A process where the stretching of the cervix during childbirth stimulates the release of oxytocin, leading to stronger contractions and further stretching.

Another example of a positive feedback loop. Hormones released by ripening fruits stimulate neighboring fruits to ripen, creating a chain reaction.

A type of asexual reproduction in prokaryotes where DNA replication leads to the formation of two identical cells.

Halves of a duplicated chromosome held together at the centromere, normally forming an "X" shape during cell division.

The first stage of the cell cycle is where cells grow and prepare for DNA replication. It is a crucial checkpoint before entering the S phase.

The stage in the cell cycle where DNA is replicated occurs between G1 and G2 phases. Ensures each daughter cell receives a complete set of genetic information.

A stage in the cell cycle where the cell prepares for division after DNA replication in the S phase. It precedes the M phase (mitosis).

Cell division process resulting in two genetically identical daughter cells, crucial for growth, repair, and asexual reproduction.

Cell division process forming haploid gametes from diploid germ cells, leading to genetic variation.

Cell cycle phase where cells grow, replicate organelles, and DNA before entering mitosis.

First stage of mitosis where chromatin condenses into chromosomes, nuclear envelope breaks down, and spindle fibers begin to form.

Stage of mitosis where chromosomes align in the middle of the cell, ready to be separated into two daughter cells during anaphase.

the stage in mitosis or meiosis where sister chromatids separate and move towards opposite poles of the cell.

the final stage of mitosis, where the chromosomes arrive at opposite poles and a new nuclear membrane forms around each set.

Network of protein filaments aiding in chromosome movement during cell division, crucial for proper segregation.

The cell cycle phase is where cells are non-dividing, either in a quiescent stage or a post-mitotic state. Where the cell is functioning.

The control mechanism that is crucial for normal growth and development, varying from cell type to cell type.

Protein-based cell signals crucial for regulating the cell cycle, increasing in concentration from S phase until Anaphase.

Key control points in the cell cycle that regulate progression and ensure proper division.

An active enzyme formed by the combination of Cyclins with Cyclin dependent Kinase (CdK), initiating mitosis.

An enzyme present in cancer cells that prevents telomeres from shortening, allowing cells to evade apoptosis and become “immortal”. Also occurs whilst humans are in development but stops after birth.

The process of creating new blood vessels to supply nutrients to tumors in cancerous cells.

The process where the DNA in a cell is altered, often leading to the initiation of cancer, such as the activation of telomerase.

The enzyme that adds phosphate groups to molecules, often proteins, to regulate cell processes like growth and metabolism.

A series of molecular events triggered by a signaling molecule binding to a receptor, leading to a cellular response.

Signaling molecules are produced in response to the activation of cell surface receptors, amplifying and transmitting the signal inside the cell.

A signaling molecule that regulates various cellular processes by activating protein kinase Secondary messenger in most cells.

CA2+ is a crucial ion in biology involved in muscle contraction, cell signaling, and bone formation. It plays a key role in processes like neurotransmitter release and enzyme activation. Secondary messenger.