IB Bio: Cell Biology

The cell is the basic unit of life, all living things are composed of cells, and cells come from prexisting cells

Cell Theory

Discovered cells (1663)

Robert Hooke

Invented the compound microscope (1590)

Zacharias Jansen

Discovered unicellular organisms (1674)

Anton Von Leeuwenhoek

Concluded that plants are made of cells (1838)

Matthias Schleiden

Concluded that animals are made of cells (1839)

Theodore Schwann

Concluded that all cells come from other cells (1855)

Rudolf Virchow

Developed the modern compound microscope (1886)

Ernst Abbe / Carl Zeiss

A claim that has been shown to be true through repeated observation and experiments. There is no current doubt.

Scientific Theory

Cellular Structure, Metabolism, Reproduction, Sensitivity and Response, Obtain Energy and Matter, Homeostasis, Excretion, Growth

The 7 Functions of Life

One of the 7 functions of life: all living things are made of cells

Cellular Structure

One of the 7 functions of life: All life can create chemical reactions within a cell

Metabolism

One of the 7 functions of life: All life can reproduce

Reproduction

Reproduction with two parent organisms

Sexual Reproduction

Reproduction with one parent organism

Asexual Reproduction

One of the 7 functions of life: All life can recognize and respond to environmental stimuli

Sensitivity and Response

One of the 7 functions of life: All organisms can acquire energy and matter to maintain a metabolism

Obtain Energy and Matter

Organisms that get energy from abiotic sources

Autotrophs

Organisms that get matter from other biotic sources

Heterotrophs

One of the 7 functions of life: All life can keep its internal environment stable

Homeostasis

One of the 7 functions of life: All life can excrete waste

Excretion

One of the 7 functions of life: all living things can grow and develop

Growth

All populations can adapt over time

Adapt and Change

The ratio of cell surface area to volume that determines the efficiency of the cell

SA:V Ratio

An organism that is made of a singular cell

Unicellular Organism

An organism that is made of multiple cells

Multicellular Organism

A group of cells that specialize in the same way and perform the same function

Tissue

The development of specialized structures in a cell due to differences in gene expression

Differentiation

The process in which information from a gene is used to make a product, generally a protein

Gene Expression

When DNA is changed to form RNA

Transcription

When RNA is changed to form a protein

Translation

Cells that can divide infinitely to create more stem cells and can differentiate to become different cell types within a multicellular organism

Stem Cells

Stem cells that can become any body cell

Totipotent Stem Cells

Stem cells hat can become any non-placenta cell

Pluripotent Stem Cells

Stem cells that are partially differentiated, but can still become multiple related cell types

Multipotent Stem Cells

Recessive disease that causes progressive vision loss that can be treated with stem cells

Stargardt's Disease

A genus of unicellular, eukaryotic, heterotrophic organisms

Paramecium

How much larger an object appears compared to its real size

Magnification

Ocular Magnification + Objective Magnification

Total Magnification

A device which produces a magnified image of objects too small to be seen with the naked eye

MIcroscope

The diameter of the area visible through a microscope

FOV

((Diameter on Low Power) * (Magnification of Low Power Objective)) / (Magnification of High Power Objective)

Equation to find FOV Diameter on High Power

A photo taken through a microscope

Micrograph

(Measured Size of Drawing) / (Size of Specimen)

Drawing Magnification Equation

Relatively small cells with 70s ribosomes without membrane-bound organelles found within unicellular organisms

Prokaryotic Cells

Relatively large cells with 80s ribosomes with membrane-bound organelles found within both unicellular and multicellular organisms

Eukaryotic Cells

Relatively light ribosomes found within prokaryotic cells, mitochondria, and chloroplasts

70s Ribosomes

Relatively heavy ribosomes found within eukaryotic cells

80s Ribosomes

Theory that states mitochondria and chloroplasts evolved from symbiotic prokaryotes engulfed by larger cells

Endosymbiotic Theory

Measurement of ribosome weight/particle sedimentation

Svedberg Unit

Cell structure that regulates what enters and exits the cell

Cell Membrane

Circular DNA not wrapped around proteins found within prokaryotic cells

Nucleoid

Gel-like fluid within the cell where metabolic reactions take place

Cytoplasm

Organelles that create proteins that are found in all cells

Ribosomes

Extra areas of DNA within a prokaryotic cell

Plasmids

Cell structure that protects the cell's shape and prevents bursting

Cell Wall

Cell structure that allows a cell to attach to surfaces and swap and harpoon DNA

Pilli

Cell Structure that keeps the cell from dehydrating

Capsule

Tail-like cell structure used for locomotion

Flagellum

Any cell structure outside of the cell membrane

Extracellular

Cells that have organelles separate from the rest of the cell which are bound by membranes

Compartmentalized

Asexual reproduction occurring in prokaryotes, protists, and organelles used for reproduction in which no spindle apparatus is formed

Binary Fission

Prepare for division, DNA replication, DNA attachment, Pinching in, Division, Daughter Cells

Steps of Binary Fission

Prepare for Division: The parent cell must have enough energy and resources to divide

1st Step of Binary Fission

DNA Replication: DNA within a nucleoid is semi-conservatively replicated

2nd Step of Binary Fission

DNA Attachment: The two DNA molecules attach to different parts of the cell membrane. The cell then builds more cell wall and cell membrane, elongating the cell

3rd Step of Binary Fission

Pinching In: The cell membrane and cell wall continue to grow and pinch in, creating furrows at the edge

4th Step of Binary Fission

Division: The furrows eventually meet and cause the cell to split in two

5th Step of Binary Fission

Daughter Cells: Two daughter cells are formed that are identical to the parent cell

6th Step of Binary Fission

The smallest interval distinguishable by a microscope, which corresponds to the detail of the image

Resolution

Microscopes that bend light to magnify, can show living cells in color, have a 2000x magnification and 200 nm resolution

Light Microscope

Microscopes that bend electron beams to magnify, can only show dead cells, have a 250000x magnification and 0.2 nm resolution

Electron Microscope

Organelle that contains DNA and the nucleolus

Nucleus

Organelle comprised of membrane sacs with ribosomes that synthesizes proteins

Rough Endoplasmic Reticulum (RER)

Organelle comprised of membrane sacs without ribosomes that synthesizes phospholipids

Smooth Endoplasmic Reticulum (SER)

Small containers created by the cell to transport molecules into, around, and out of the cell

Transport Vesicle

Organelle that sorts and packs vesicles

Golgi Apparatus

Organelle that contains enzymes needing low amounts of oxygen or low pH

Lysosome

Organelle that contains enzymes needing high amounts of oxygen

Peroxisome

Organelle that creates ATP< which is used as energy for the cell

Mitochondria

Organelle found in plant cells that photosynthesize

Chloroplast

Organelle that stores water

Vacuole

Lipids that are a major component of cell membranes with a hydrophilic head and two hydrophobic tails

Phospholipids

The layer of phospholipids forming the cell membrane

Phospholipid Bilayer

Molecules, generally polar or ionic, that attract water molecules

Hydrophilic

Molecules, generally non-polar, that repel water molecules

Hydrophobic

A single molecule that contains both hydrophobic and hydrophilic parts

Amphiphatic

Disproven model of the phospholipid bilayer that states that there is a lipid layer between two protein layers

Davson-Danelli Model (1935)

Model of the phospholipid bilayer that states that proteins are within the bilayer

Singer-Nicolson Model (1972)

Proteins that loosely attach to the hydrophilic heads of the phospholipid bilayer

Peripheral Proteins

Proteins that lock onto the hydrophobic tails of the phospholipid bilayer

Integral Proteins

Transporting solutes across the cell membrane without using ATP, moving to areas of low concentration

Passive Transport

Proteins that form pores that extend across the phospholipid bilayer

Channel Transport Proteins

Proteins that change shape to transport solutes across the cell membrane

Carrier Transport Proteins

Proteins that pump solutes across the cell membrane

Pump Transport Proteins

Proteins embedded within the cell membrane which bind to specific exterior chemical signals, causing a response from the cell

Receptor Proteins

Proteins that catalyze chemical reactions

Enzyme Proteins

Proteins that are embedded in the cell membrane that allow cells to identify and interact with one another

Recognition Proteins

Proteins that interact with other cells through cell adhesion

Adhesion Proteins

Proteins made up of carbohydrate chains, generally recognition proteins

Glycoproteins