Unit 1-2

The basic structural and functional units of every organism:

Cells

What applies to all cells?

Bound by plasma membrane, contain cytosol / cytoplasm, contain chromosomes, contain ribosomes

What are the type of cells?

Prokaryotes and eukaryotes

What are the domains of prokaryotes?

Bacteria and archaea

Where is DNA in prokaryotes?

Nucleoid region

Size of prokaryotes vs eukaryotes:

Smaller

What do eukaryotes include?

Protists, fungi, animals, plants

Where is DNA in eukaryotes?

Nucleus

What do eukaryotes contain?

Membrane bound organelles

Membrane bound structures in eukaryotes:

Organelles

What types of organelles are there?

Endomembrane organelles and energy organelles

Endomembrane organelles include:

Nuclear envelope, endoplasmic reticulum, golgi complex, lysosomes, vesicles / vacoules, plasma membrane

What do energy organelles include?

Mitochondria and chloroplasts

What does compartmentalization in organelles allow for?

Different metabolic reactions to occur in different locations

What does compartmentalization increase?

Surface area for reactions to occur

What does compartmentalization prevent?

Interfering reactions occuring in same location

Unique plant cell components:

Chloroplasts, central vacoule, cell wall, plasmodesmata

Holes in cell wall that fluids can use to get in and out:

Plasmodesmata

Unique animal cell components:

Lysosomes, centrosomes, flagella

What does nucleus contain?

Chromosomes, nucleolus

What do chromosomes carry?

Genetic information

What is the nucleus enclosed by?

Nuclear envelope

What type of membrane is the nuclear envelope?

Double membrane

What does the nuclear envelope have?

Pores

What do pores on the nuclear envelope regulate?

Entry and exit of materials from cell

Dense region of the nucleus where ribosomal RNA is synthesized:

Nucleolus

What is rRNA combined with proteins to form?

Large and small subunits of ribosomes

What do ribosome subunits exit via?

Nuclear pores

What do ribosomal subunits assemble into?

Ribosomes

What do ribosomes translate?

Message found on mRNA into primary structure of polypeptides

Is DNA found in nucleus or nucleolus?

Nucleus

Where do ribosomal subunits assemble into ribosomes?

Cytoplasm outside nucleus

What are ribosomes comprised of?

Ribosomal RNA and protein

Why do some texts not classify ribosomes as organelles?

They are not bound by membrane

Function of ribosomes:

Synthesize proteins

Where can ribosomes be found?

Cytosol (cytoplasm) or bound to endoplasmic reticulum or nuclear envelope

Where do proteins produced in the cytosol generally function within?

Cytosol

Example of proteins produced in cytosol that generally function only within cytosol:

Enzymes

What are ribosomes found in the cytosol called?

Free ribosomes

What can happen to proteins bound to the endoplasmic reticulum or nuclear envelope?

Secreted from cell

What do proteins bound to endoplasmic reticulum or nuclear envelope leave the cell via?

Transport vesicles

A network of membraneous sacs and tubes:

Endoplasmic reticulum

Functions of endoplasmic reticulum:

Synthesizes membranes, compartmentalizes cell to keep proteins formed in rough ER separate from those of free ribosomes

Types of endoplasmic reticulum:

Rough and smooth

What does rough ER contain?

Ribosomes bound to ER membrane

What does rough ER make?

Proteins needed outside cell

Does smooth ER contain ribosomes?

No

What does smooth ER do?

Synthesize lipids, metabolize carbohydrates, detoxifies cell

What does metabolize mean:

Breaking down to use

What does golgi complex contain?

Cisternae

What are cisternae?

Flattened membranous sacs

What does golgi complex separate?

Sacs from cytosol

Is each cisternae connected?

No

What does golgi complex have?

Directionality

Faces of golgi complex:

Cis and trans

What does cis face do?

Receive vesicles from ER

What does trans face do?

Send vesicles out to cytosol to other locations or to plasma membrane for secretion

Functions of golgi complex:

Receive transport vesicles with matierals from ER, modify materials, sort materials, add molecular tags, package materials into new transport vesicles that exit membrane via exocytosis

What does the golgi complex modfying materials ensure?

Newly formed proteins folded or modified correctly

Membranous sac with hydrolytic enzymes:

Lysosome

Functions of lysosomes:

Hydrolyzes macromolecules in animal cells, autophagy

What can lysosomes recycle?

Own cell’s organix materials

The process of lysosomes recycling their own cells’ organix materials:

Autophagy

What does autophagy allow for?

Cells to renew itself

What are peroxisomes similar to?

Lysosomes

What kind of compartment are peroxisomes?

Membrane bound metabolic compartment

What do peroxisomes catalyze?

Reactions that produce H2O2

What do enzymes in peroxisomes break down?

H2O2 into water

Large vesicles that stem from ER and golgi:

Vacoules

What are vacoules selective in?

Transport

Types of vacuoles:

Food, contractile, central

What do food vacuoles form via?

Phagocytosis

What does phagocytosis mean?

Cell eating

What are food vacuoles digested by?

Lysosomes

What does contractile vacuole maintain?

Water levels in cells

What are central vacuoles found in?

Plants

What do central vacuoles contain?

Inorganic ions and water

What are central vacuoles important for?

Turgor pressure

Steps in autophagy:

Membrane forms around cellular component targeted for degradation, membrane engulfs cellular component, fuses with lysosome, hydrolytic enzymes in lysosomes digest organelles and recycle their components

What does membrane engulfing cellular components during autophagy form?

Autophagosome

At the end of the autophagy process, which components are released back into cytoplasm?

Amino acids and other small molecules

Steps in protein synthesis:

Transcription and RNA processing, translation, folding and modification, secretion or use in cell

Where does transcription occur?

Nucleus

What does mRNA serve as?

Template to assemble protein

Why does mRNA undergo processing?

To prepare for translation

DNA sequence of gene copied into mRNA:

Transcription

What does processed mRNA exit?

Nucleus

What does processed mRNA exit nucleus through?

Nuclear pores

What translates mRNA?

Ribosomes

What translates mRNA that codes for proteins destined for secretion, insertion into cell membrane, or lysosomes?

Ribosomes bound to rough ER

What happens to proteins after translated by ribosomes bound to rough ER?

Sent to golgi

What translates mRNA that codes for proteins that function in cytosol?

Free ribosomes in cytoplasm

What happens to protein after being translated by free ribosomes in cytoplasm?

Discharged in cytoplasm

The process where ribosomes read mRNA sequence and translate it into polypeptide chain:

Translation

Sequence of amino acids:

Polypeptide chain

What happens to polypeptide chain after translation?

Folds into specific 3D shape

What does rough ER do to protein?

Package into vesicles

Diagram of translation:

Where do vesicles that bud off from rough ER travel to?

Cis face of golgi apparatus

What happens to proteins in golgi apparatus?

Undergo further modifications