Ace The MCAT Course - Biology Videos Flashcard

Cell Theory

Cell Theory

1. All Cells are made up of Cells

2. Cells are basic Unit of Life

3. All Cells come from pre-existing cells

Endomembrane System (endo- = “within”)

A group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins.

• Nuclear envelope

• Golgi apparatus

• Endoplasmic reticulum

• Vesicles

• Lysosomes

Nucleus

• Site of DNA - Transcription happens here

• Controls center of the cell

• Contains genetic materials

Nucleolus

• Inside the nucleus

• Makes ribosomes. Sits in nucleus, no membrane

Nucleoid Region

DNA region in prokaryotes

Ribosomes

• Makes Proteins

• 30S and 40S is where translation occurs

Endoplasmic Reticulum

• Smooth ER

  • Detoxification

  • Lipid Synthesis

• Rough ER

  • Embedded in ribosomes

  • Accept mRNA to make proteins.

Plays a key role in the modification of proteins and the synthesis of lipids. It consists of a network of membranous tubules and flattened sacs. The discs and tubules of the ER are hollow, and the space inside is called the lumen

Mit

Golgi Apparatus

• Put proteins in vesicle and prepare them for execration (being released from the cell)

• Package proteins - Protein secretion

• Modify / distribute proteins. Only in eukaryotes

Lysosomes

• Demo & Recycling center. Made by Golgi. Single membrane

• Contains hydrolytic pyrolytic enzymes - breakdown proteins

  • Phagocytosis

  • Exocytosis

  • Endocytosis

  • Pinocytosis

• Endocytosis (endo= in)

• Exocytosis (exo= out)

  • Pinocytosis: Ingestion of liquids via vesicles

  • Phagocytosis: Ingestion of larger solid materials

• Methods of engulfing material into the cells or releasing material out of the cell.

Cytoplasm

• Glycolysis occurs here

Cytosol

Liquid section of the cytoplasm

Peroxisomes

Collect and break down material.

Mitochondria

ETC Occurs here

Got their own DNA

Lysosomes

Cytoskeleton

Microfilaments: Actin

Microtubules: Tubulin

Intermediate Filaments: Keratin = Vimentin; Desmin = Lamin

Tight Junction

Cells meet together so tightly that no liquid can get in.

• The cell is sealed and noting can get inside

Gap Junction

Channels and pores between cells

• Ions and some materials can be exchanged

Desmosome

Connected at one point of the cell