Module 1: Week 2 Intro to Phys Flashcards
What is a cell?
The smallest structural units of living things.
What are organelles?
LIttle Organs, Structures within the cell that have specialised shapes and functions. Organelles facilitate the metabolism of the cell.
Types of organelles can indicate:
Cell function
Cell biology is:
The study of cellular structure and function.
What are the three main parts of the cell?
Plasma membrane
Cytoplasm
Nucleus
What is the plasma membrane?
The outer layer of the cell.
What does the plasma membrane do?
Forms a selective barrier to the cell, guarding what comes in/goes out.
Helps healthy cell function.
Allows communication between cells and environment outside cell.
What is the cytoplasm?
Everything within the cell, from the nucleus to the plasma membrane.
What are two compartments of the cytoplasm?
a) cytosol (fluid)
b) organelles
Cytosol is:
Fluid inside cells: water, solutes, suspended particles
List some organelles:
Mitochondria Rough endoplasmic reticulum Smooth endoplasmic reticulum Ribosomes Golgi complex Cytoskeleton Lysosomes Peroxisomes Nucleus
What is the nucleus?
Large organelle.
Contains DNA -contains genes:genetic material/coding.
Drives cellular function.
Directs how cell reproduces.
What does a typical cell look like:
No such thing as a typical cell. Each type of cell is specialised.
What do ribosomes do and where are they found in the cell?
Ribosomes synthesise proteins, using the genetic template provided by messenger RNA.
Ribosomes are found in the cell, free. The proteins made by free ribosomes are used by the cell.
Ribosomes are found in and on the rough endoplasmic reticulum and proteins synthesised here are packaged up by the Golgi Complex and leave the cell.
What does the Golgi Complex do?
Aust Post of the cell. Accepts, modifies, sorts molecules for transport, including synthesised proteins.
What do Mitochondria do?
Powerhouse of cell - place of cell metabolism. Produces ATP (energy currency) aerobically.
What does the Smooth Endoplasmic Reticulum do?
Synthesises lipids, phospholipids and glycoproteins.
What is the plasma membrane made of?
A bilayer of phospholipids…. Hydrophilic (polar)heads outward facing, exposed to intracellular and extracellular fluid. Hydrophobic tails (non-polar) on inside of membrane.
Transmembrane proteins - passage through membrane
Cholesterol (20%) - OH group forms hydrogen bonds with hydrophilic heads - stabilises bilayer
Peripherol proteins - cell identification (outer side)
Glycolipids (5%) - in part of layer facing extracellular fluid
The cell membrane is selectively…
permeable
Two types of movement across the cell membrane:
Passive (diffusion/concentration gradients-high to low) - requiring no energy from cell
Active (active transport) - requiring ATP - protein transporters involved
Peripheral proteins are:
On the outside of the membrane - attached to polar heads. Involved in cell identification.
Transmembrane Proteins are:
Involved in transport across the plasma membrane. Go through the entire bilayer, exposed to both intracellular fluid and extracellular fluid.
Some have a constantly open channel. Others have gates that open and close.
What are three types of passive transport?
Simple diffusion
Facilitated diffusion (channel-mediated facilitated diffusion & carrier-mediated facilitated diffusion)
Osmosis
What is Channel-Mediated Facilitated Diffusion?
Charged ions such a sodum (Na+) or Potassium (k+) travel through protein channels into the cell.
