Cell Structure & Function — Easy Memorization Guide

A comprehensive vocabulary flashcard set covering cell structure, organelles, microscopy, cell fractionation, and extracellular components based on the lecture notes.

Light Microscope

A microscope that uses light + glass lenses, Magnifies up to 1,000×, Resolution ≈ 200 nm, Stains improve contrast, Can study living cells

Electron Microscope

A microscope that uses a beam of electrons, Electrons have shorter wavelengths, Better resolution than light microscopes, Theoretical resolution: 0.002 nm, Practical resolution: about 2 nm, Specimen is coated with metal (ex: gold), Cannot study living cells because specimen is killed.

TEM (Transmission Electron Microscope)

A type of electron microscope where electrons pass through a thinly sliced specimen to show internal cellular structure.

SEM (Scanning Electron Microscope)

A type of electron microscope that scans the surface of a metal-coated (ex: gold) specimen to reveal 3-D surface details.

Confocal Microscopy

A microscopy technique using fluorescent markers to produce 3-D images of cellular structures.

Super-resolution Microscopy

A microscopy technique using fluorescent markers that can resolve cell structures down to around 10–20 nm.

Cell Fractionation

A laboratory technique using a centrifuge to spin cell mixtures and separate organelles by size to study their functions.

Pellet

The heavier material that settles at the bottom of a tube after centrifugation during cell fractionation.

Supernatant

The liquid remaining above the pellet at the top of a tube after centrifugation.

Organelle Centrifugation Order (Never Make Pizza Regularly)

The order in which organelles pellet out by size during cell fractionation: Nucleus → Mitochondria → Plasma membrane → Ribosomes.

All cells including prokaryotic and eukaryotic cells have this (My Cells Do Run)

The four structural components present in all cells: Membrane, Cytosol, DNA/chromosomes, and Ribosomes.

Eukaryotic Cell

A cell type characterized by having DNA enclosed within a membrane-bound nucleus.

Prokaryotic Cell

A simple cell type that lacks a nucleus, with its DNA located in an unbound region called the nucleoid. It has naked dna meaning its unprotected and typically smaller in size compared to eukaryotic cells. Prokaryotic cells are usually unicellular organisms, such as bacteria.

Surface-Area-to-Volume Ratio (SA:V)

The ratio comparing surface area to volume; smaller cells have a higher SA:V ratio, enabling more efficient exchange of materials with the environment.

Nuclear Envelope

The membrane surrounding the nucleus

Nuclear Lamina

protein filaments that provides structural support to the nuclear envelope.

Chromatin

The complex of DNA and proteins that make up chromosomes

Free Ribosomes

Ribosomes that make proteins used in cytosol

Bound Ribosomes

Ribosomes attached to membranes that synthesize proteins go into membranes, organelles, or export/secretion.

Smooth ER

A region of the endoplasmic reticulum that lacks ribosomes and functions in lipid synthesis (oils, phospholipids, steroids), carbohydrate metabolism, drug/alcohol detoxification, and $Ca^{2+}$ / calcium storage.

Rough ER

A region of the endoplasmic reticulum that has ribosomes attached that synthesizes secretory (produced by cell and getting released into the outside of a cell) proteins, membrane proteins, glycoproteins, and membrane phospholipids.

Glycoprotein

protein+carbohydrate.

Golgi Apparatus

An organelle that receives products from the ER (Proteins) to modify, sort, store, and ship them to their final destinations.

Cis Face (Golgi)

The receiving side of the Golgi apparatus where products arriving from the ER enter.

Trans Face (Golgi)

The shipping side of the Golgi apparatus where modified products depart in vesicles for their destinations.

Lysosome

A membrane-bound organelle containing hydrolytic enzymes that digest macromolecules and cellular waste/autophagy and play a key role in programmed cell death.

Phagocytosis

The cellular process where a cell eats something

Autophagy

The lysosomal process where a cell recycles its own organic material and damaged organelles.

Tay-Sachs Disease

A condition in which lipids accumulate in the brain due to defective lysosomal digestion, impairing mental development.

Contractile Vacuole

A vacuole in protists/algae that contracts to pump excess water out of the cell.

Central Vacuole

A large vacuole in plant cells that stores inorganic ions and aids in cell growth.

Cristae

inner membrane folding that contains proteins that make ATP (ETC located here)

Mitochondrial Matrix

The fluid-filled inner space of a mitochondrion containing DNA, ribosomes, and enzymes for some steps of cellular respiration.

Thylakoid

A flattened, membranous sac inside a chloroplast involved in photosynthesis.

Granum

A stack of thylakoid membranes within a chloroplast.

Stroma

The dense fluid surrounding the thylakoids inside a chloroplast.

Peroxisome

organelle that breaks down harmful substances and fatty acids like hydrogen peroxide, into water and oxygen.

Microtubules

Cytoskeletal elements that support cell shape, act as tracks for organelle movement, grow from centrosome, guide secretory vesicles, and form cilia and flagella.

MicroFILAMENTS→ ACTIN → ACTION

Cytoskeletal elements made of actin that support cell shape, assist in muscle contraction with myosin, and enable amoeboid movement.

Intermediate Filaments = stable

Permanent cytoskeletal fibers that provide maintains cell shape, anchor organelles and the nucleus, and form the nuclear lamina

9 + 2 Structure

The microtubule arrangement in motile cilia and flagella consisting of 9 outer doublets surrounding 2 central single microtubules.

Dynein

A motor protein in cilia and flagella that uses ATP to move along microtubules and generate bending movements.

Primary Cell Wall

A thin and flexible wall layer secreted by plant cells.

Middle Lamella

A pectin-rich layer between primary walls of adjacent plant cells that glues neighboring cells together.

Secondary Cell Wall

A strong, protective wall layer added between the plasma membrane and primary cell wall in mature or woody plant cells.

Collagen

The most common glycoprotein in the animal extracellular matrix (ECM) that provides structural support.

Proteoglycans

A network surrounding collagen

Fibronectin

An ECM glycoprotein that binds to integrin receptor proteins in the plasma membrane.

Integrins

Cell-surface receptor proteins that connect the extracellular matrix to the interior cytoskeleton and transmit signals.

Desmosomes

Fastens cells together strongly

Tight junctions = Seal

Seals spaces between cells and prevent leakage of extracelluar fluid

Plasmodesmata

Channels between plant cells that connect neighboring plant cells.

Gap Junctions = gate

Small pores allowing certain molecules to pass between animal cells

CILLA vs FLAGELLA

Cilla shorter and numerous and flagella longer and fewer both help with movement

Where do contractile vacuoles in protists/algae live?

They live in freshwater which is hypotonic

What’s hypotonic?

Concentration of solutes is lower than that of inside a cell and more water goes in than out resulting in cell swelling.

What’s hypertonic?

Concentration of solutes is higher than that inside a cell, causing water to move out, resulting in cell shrinkage.

How do plant cells grow?

Plant cells pump water to create turgor pressure and grow in one direction by expanding their cell walls and increasing volume.

Why do only nearly all eukarytoic cells have a mitrochronia?

Some protists have lost their mitrochondria because they are parasites and use ATP

What is the number of mitochondria correlated with?

The cell’s metabolic activity.

Similarities between mitochondria and choloroplast

2 membranes, each a is phosphlipid bilayer

What’s the endosymbiont theory of orgin?

The endosymbiont theory of origin proposes that mitochondria and chloroplasts originated from free-living bacteria that were taken into early cells. Both benefited from living together. Example: Green algae, Chlorella lives in paramecium.

What came first during the evolution between eukaryotic cells and why? Chloroplast or Mitochondria

Mitochondria became first because all eukaroytic cells contained this until some bacteria lost it later on.

Why do we need oxygen in mitochondria

The mitochondria acts as the final ETC in celluar respiration, allowing cells to efficiently produce ATP.

What is microtubles job?

Act as tracks that motor proteins travel along while carrying cargo ; Example guiding secretory vesicles from golgi to plasma membrane

Job of the trachea and cilla

Sweep mucus out of lungs

What are cillia and flagella mostly made out of?

Microtubules

Motion of Flagella and Cillia (TEST)

Flagella has a circulating motion while cilia have a back-and-forth motion such as power and recoery strokes.

Nonmotile cillia pattern

9+0

Difference between motile cillia vs non-motile

Motile cillia move alot and have to bend, have a back and forth pattern, moves fluid or particles across cell while non-motile cillia dont actively move, act as a sensory antennas, and help cell detect signals from its environment.

What is the function of the plasma membrane?

The plasma membrane regulates the movement of substances in and out of the cell, maintaining homeostasis while providing protection and support. It is also involved in cell communication and signaling.

What cell is desmosomes found in?

Animal

What cell are gap junctions found in?

animal

What cell are tight junctions found in?

animal

What cell is the Plasmodesmata found in?

Plant