AP Bio Unit 2 Vocab Examples

You must guess what term or principle the front example is describing.

Surface area to volume ratio of cells

Because prokaryotic cells are so small, having way more surface area compared to volume, they are allowed to be simple because they can transport materials in themselves more efficiently.

Cytoplasm

No need for an example. It’s everything inside the cell excluding the nucleus

Cytosol

No need for an example. It’s the gel-like substance that fills a cell and holds the organelles.

Nucleoid

Quinolone antibiotics interfere with DNA replication in bacteria, thus affecting the nucleoid region that contains their DNA.

Cell wall

Plants are crunchy because their cells have a wall made of cellulose around them that provides strong structure and support.

Flagella

E. coli has multiple whip-like tails that allow it to move.

Capsule (prokaryotes)

Streptococcus pneumoniae is surrounded by a capsule that allows it to more easily survive against the body’s immune system. This makes bacterial pneumonia more severe than viral pneumonia, and it requires antibiotics that target the capsule, when viral pneumonia can sometimes resolve on its own.

Endosymbiont theory

Mitochondria and chloroplasts have their own DNA, have double membranes, divide via binary fission, and have ribosomes, just like prokaryotic cells. This evidence supports the theory that mitochondria and chloroplasts were once prokaryotes and were absorbed by eukaryotic cells.

Selective permeability

Nonpolar molecules like CO2, diatomic elements, and hydrocarbons can pass through the plasma membrane passively, while polar molecules like H2O and NH3 can’t and require active transport.

Fluid-mosaic model

The structure of the cell membrane is made of a flexible layer made of lipid molecules with proteins embedded, allowing for mobility and a dynamic nature. This model explains how various components of the membrane can move freely, contributing to its functionality.

Adhesion proteins

In cancer, proteins called cadherins play an important role in keeping the cells in tumors together. When cancer metastases, the cadherins allow the tumor cells to stick to multiple places in the body.

Receptor proteins

Insulin receptors serve as a docking site for insulin secreted by the pancreas and trigger cellular responses such as glucose uptake and metabolism.

Transport proteins

The sodium-potassium pump actively moves sodium out of and potassium into cells against their concentration gradients, playing a crucial role in maintaining membrane potential.

Channel proteins

Aquaporins are like gates that facilitate the movement of water molecules across the cell membrane, regulating water balance in cells.

Cell surface markers

Antigens on the surfaces of cells are detected by immune cells via receptors to tell whether it is safe or a foreign object that must be elimnated.

Function of the nucleus

You already know it contains the genetic material in eukaryotic cells. In our skin cells, it also regulates the production of keratin, responses to external stimuli, and cell division processes.

Ribosomes

Anemia can be caused by ribosomopathies, which impacts the organelles responsible for protein synthesis and impairs red blood cell development.

Small and large subunits

The ribosomes in bacteria are made of two parts called 30S and 50S. The ribosomes in your own cells are made of two bigger parts called 40S and 60S.

Rough endoplasmic reticulum (ER)

It is shown that in neurodegenerative diseases, the production of misfolded proteins in brain cells causes an imbalance between the synthesis of new proteins and its ability to process newly synthesized proteins. This produces a stress response by the organelle responsible for processing proteins that can lead to the death of neurons.

Smooth ER

Analogy: chemical plant that provides flexibility and detoxifies harmful substances, as well as synthesizes lipids and hormones.

Golgi complex

Analogy: post office that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Mitochondria

A genetic disease called mitochondrial encephalopathy is caused by mutations in an organelle’s DNA affecting the its ability to make certain proteins and convert oxygen to energy, leading to neurological problems and muscle weakness.

Cristae

Those folds you see inside that mitochondria on your crusty textbook? They increase surface area for ATP production and they have a name.

Lysosome

In individuals with Tay-Sachs Disease, this organelle is unable to break down specific lipids due to a mutation leading to a missing enzyme, leading to their accumulation in the nerve cells, ultimately causing severe neurological damage that leads patients to die in early childhood.

Centrioles

In the beginning stage of mitosis, these cylindrical structures produce spindle fibers that help separate chromosomes during cell division.

Vacuole

When you overwater your plants, an organelle in their cells will swell as it absorbs more water to maintain turgor pressure. This can damage the plant due to decreased availability of nutrients.

Peroxisome

Analogy: toxic waste management for cells, breaking down hydrogen peroxide and fatty acids.

Cytoskeleton

Analogy: foundational structure, made of fibers like microtubules and microfilaments, of the building that is the cell.

Vesicles

As part of the immune response, white blood cells kill bacteria and viruses by engulfing them in a sac-like organelle and eating them.

Homeostasis

Humans regulate their body temperature through processes like sweating or shivering to maintain a stable internal environment.

Passive transport: diffusion

Without any energy, O2 moves out the alveoli of the lungs (high concentration) into the bloodstream (low concentration) via a process of passive transport.

Passive transport: osmosis

If you put a gummy bear in water, it will swell as it absorbs the water via a process of passive transport.

Simple vs. facilitated diffusion

O2 automatically diffusing from the alveoli into the bloodstream vs. glucose needing a protein channel to enter the cell

(1) Isotonicity, (2) hypertonicity, and (3) hypotonicity

1. Nothing happens to a cell because the concentration of solute in its cytoplasm is the same as its environment.

2. The cell will shrivel as it loses water because there is a higher concentration of solute outside the cell than inside.

3. The cell will bloat as it absorbs water due to a lower concentration of solute outside than inside.

Water potential

Seawater has very low ________ because it is full of dissolved salts that create osmotic pressure and prevent free movement of water molecules.

Solute potential

A plant wilting due to low water potential caused by too high concentrations of nutrients in very little water.

Pressure potential

A plant wilting due to low water potential caused by too little turgor pressure in the cells.

Active transport

The sodium-potassium pump requires ATP/energy to operate and transport Na+ and K+ even against the concentration gradient.

Osmoregulation

Organisms like mammals urinate to expel excess electrolytes and maintain water and salt balance in their bodies. Cells do kinda the same thing.

Phagocytosis vs. pinocytosis vs. mediated endocytosis

White blood cells engulfing bacteria in a vesicle to eat and kill them vs. small intestine villi engulfing fat droplets vs. LDL receptors on liver cells binding with LDL particles to bring them into the cell.

Bulk flow

Blood moves through your blood vessels because of pressure differences created by the heart.

Dialysis

When your 90-year-old grandpa with kidney failure undergoes ______, a machine has his blood pass through a tube into a filter with selectively permeable parts that removes waste products and excess fluid via diffusion before returning it to his body.