Midterm paper

CELL BIOLOGY LAB Pre-lab Resources

Dr. Lisa Brinn

Learning Outcomes

■ Identify the structures of an animal cell.

■ Outline the functions of the membranous and some non-membranous organelles.

Cells

■ Smallest living units

■ Common structures – Cell membrane – Cytoplasm – DNA

■ Categories – Eukaryotic ■ Have organelles

– Prokaryotic ■ Don’t have organelles

Cell Composition ■ Cell membrane

– Function: ■ Isolate ■ Protect ■ Support ■ Control entrance and exit

■ Cytoplasm ➙ cytosol + organelles – Organelles

■ Diverse with specific functions – Cytosol

■ Contains: – Nutrients – Proteins – Wastes – Ions - ↑ concentration of K+

■ Allows for diffusion

Organelles

■ Definition – little organs

■ Examples of organelles – Nucleus – Nucleolus – Endoplasmic reticulum – Mitochondria – Golgi apparatus – Vesicles

■ Lysosomes – Peroxisome

Nucleus ■ Cell control center

■ Contains: – DNA ■ Chromatin ■ Chromosomes

– Nucleolus ■ Makes ribosomes

Endoplasmic Reticulum (ER)

1. Rough endoplasmic reticulum

2. Smooth endoplasmic reticulum

■ Functions: – Synthesis – Storage – Transport – Detoxification

Golgi Apparatus

■ Also known as: – Golgi body – Golgi complex

■ Functions: – Package enzymes for use in the cytosol – Renew or modify the plasma membrane – Synthesize and package secretions

Secretory Vesicles

1. Package enzymes for use in the cytosol – Formation of lysosomes

2. Renew or modify the plasma membrane – Golgi apparatus ■ Loses membrane by forming vesicles ■ Gains membrane by fusion of transport vesicles

– Golgi-generated vesicles ➙ fuse with plasma membrane ■ Adds to cell surface area

3. Synthesize and package secretions – Formation of secretory vesicles ➙ fuse with plasma membrane ■ Exocytosis – contents are released into extracellular fluid

Mitochondria

■ Mitochondrion (singular)

■ Double-layered membrane – Outer membrane – Inner membrane ■ Cristae (enzymes)

■ Generates chemical energy – Produces ATP ■ Breaking down organic molecules that consume O2 and generate CO2

Peroxisomes

■ Similar to lysosomes – Carry enzymes – But smaller – Carry different enzymes

■ Formed by free ribosomes inserted into pre-existing peroxisomes

■ Enzymes – Organic compounds H2O2

oxidases

catalase

H2O O2