BIOL 204 - Unit 1

What are the 3 components of the cell theory?

1. Cells are the smallest unit of life

2. All cells come from pre existing cells

3. All living organisms must have 1 or more cells to be considered living

Prokaryotic Cell

DNA and genetic material are free flowing in the cell

Examples: archaea, bacteria

Nucleoid

space where the genetic material (DNA) is in prokaryotic cell, free flowing

Prokaryotic: Pili

Hair like, outside of cell that helps attach to surfaces or other cells

Prokaryotic: Flagellum

Helps the cell move around

Prokaryotic: Ribosomes

Turn amino acids into protein with information from mRNA

Prokaryotic: Capsule

Helps defend cells from danger

Prokaryotic: Cell Wall

Protects the cell from harmful material

Cell membrane

Helps with transportation of materials in and out of the cell

Eukaryotic Cell

DNA is enclosed in the cell by an organelle called the nucleus

Nucleus

Regulates activity in the cell and holds DNA + chromosomes

Nucleoplasm

Fluid inside of the nucleus

Nuclear Envelope

A combination of nuclear pores and inner + outer membrane

Nuclear pore

mRNA out of nucleus, protein in nucleus, connect inner and outer membrane, selective to what it can let in and out

nucleolus

centre of the nucleus responsible for ribosome assembly

Chromatin

Combination of DNA and protein

Rough Endoplasmic Reticulum

Includes Ribosomes, synthesizes and transports protein

Smooth Endoplasmic Reticulum

No Ribosomes, synthesizes lipids and break down toxic substances

Cytoskeleton

Helps maintain shape and structure of the cell

Cytoskeleton: Microfilament

“Actin”, helps with cell structure, movement, and division

Cytoskeleton: Microtubule

Maintain cell shape

Ribosome

Transfer RNA to turn amino acids into protein, form chromatin

mitochondria

produce and maintain energy in the cell

lysosome

help metabolizing/break down material

Golgi Body

Recieves protein from the ER and makes final adjustments before they’re ready to be used

Endomembrane

Endoplasmic reticulum and golgi complex in Eurkaryotic Cells

Chloroplast: Amyloplast

Colourless, help with the synthesis and storage of starches

Chloroplast: granum

Stacks of Thylakoid in the chloroplast

Chloroplast: Thylakoid

Circular disks that help with the absorption of sunlight and turn ATP to NADPH

Chloroplast: Stroma

Fluid filled, where the Calvin cycle occurs

Lumen

Vital role in photosynthesis, helps with oxidizing water

Plasma Membrane (both eukaryotic and prokaryotic cells)

Helps maintain homeostasis by uptaking nutrients and eliminating waste

Semipermeable Membrane

Only allows certain material pass through the membrane

Parts of Membrane: Phospholipids

make up the cell membrane with the heads touching each other and the tails touching on the inside of the membrane, can move around and allow certain materials to pass through

Parts of Membrane: cholestrol

Help with the spacing of phospholipids

If it’s too hot, the lipids are brought together

If it’s too cold, the lipids are separated by cholestrol

What’s wrong with too much Cholestrol?

Too much cholestrol results in heart problems, as it will fill up arteries and reduce blood flow

Proteins

Transport material in and out of the cell

Peripheral Proteins

Outside of the membrane, attach to cytoskeleton

Integral Proteins

Transport materials in and out of the cell, sit kinda in and out of the membrane

4 Functions of Membrane Proteins (THAS)

Transport materials (hydrophilic)

Has enzymes

Attach to cytoskeleton

Signalling to cell

Glycolipids

Help with cell signalling and identifying the cell

What are the 2 main types of transport?

Active and Passive Transport

Passive Transport

Does not need to expend chemical energy in order to transport materials

Diffusion

Substances move from higher to lower concentration

Simple Diffusion

Molecules cross the membrane without the need of a transporter

Facilitated Diffusion

Transport materials with the help of a transporter (channel or carrier proteins), tends to be a lot faster than simple diffusion

Channel Proteins

Hydrophilic path for large molecules to pass through

What are 2 types of Channel Proteins?

Aquaporins, Gated Channels

Aquaporins

Specific type of protein that strictly transfers water

Gated Channels

Help with the movement of ions, can open and close depending on voltage

Carrier Proteins

Through phospholipid bilayer, binds to a solute before changing shapes and allowing the molecule to pass through

Active Transport

Requires energy to move molecules against the concentration gradient

2 Types of Active Transport

Primary and Secondary

Primary Active Transport

The protein breaks down ATP and transports molecules by itself

Secondary Active Transport

Needs certain concentration of ions to create energy and transport molecules

2 Categories of Secondary Active Transport

Symport and Antiport

Symport

Solute moves through channel in the same direction as the driving ion (that provides energy)

Antiport

Ions (energy) moves in a different direction as the molecule that is being transported

Phagocytosis

Cell eating

Exocytosis

A vesicle takes molecules from the inside of the cell to the outside

Endocytosis

A vesicle brings a molecule into the cell from the outside

Pinocytosis

Extracellular water is taken with the molecule (wherever it ends up)

Receptor Mediated Endocytosis

The molecule (or something) must bind to receptors before being transported into the cell

3 steps to downstream Cell Signalling

Reception, Transduction, Response

Reception

The signal molecule binds to the receptor on the cell membrane (outside of the cell)

Transduction

Receptor triggers changes in the cell

Signalling Cascade

Cascade of reactions, multiple reactions that need to happen before transduction happens

Response

The result of transduction (changes that happen in the cell)

Collagen

structural proteins in humans that are found in the extracellular matrix

Extracellular matrix

network of molecules outside of cell helping with the support and structure of the cell