Science 10: Plants and animal cells

Abiogenesis

Life comes from non-living matter. Also called spontaneous generation

Francesco Redi

Conducted experiments disproving abiogenesis. Two jars, one open and one closed. Only the open one got maggots. 

Louis Pasteur

Conducted experiments disproving abiogenesis. Distilled fluid in a swan neck flask. The fluid only went bad when the swan neck was removed proving the active principle (small living things are the reason things ferment or “go bad”)

Biogenesis

Living things come from other living things

Robert Hooke

Discovered the cell by looking at cork

Anthony van Leeuwenhoek

Discovered single celled organisms or “animalcules”

Schwann

Determined that all animals are made out of cells

Schleiden

Determined that all plants are made out of cells

Virchow

Discovered that all cells come from other cells (mitosis)

Cell theory

1. All organisms are made out of cells

2. The cell is the smallest unit of life

3. All cells come from other cells

Prokaryote

No nucleus, DNA in nucleoid region, single celled organisms, no membrane bound organelles

Eukaryote

DNA stored in nucleus, multicellular, has membrane bound organelles

Cell Membrane

Protective barriers made of proteins and lipids. Control whats goes in and out of the cell

Cytoplasm

Fluid which the organelles float in

Ribosomes

Where protein is made (protein synthesis)

Nucleus

Control center of the cell. Contains DNA

Endoplasmic Reticulum

Tubes running through the cytoplasm. Transports proteins and lipids. Rough ER has ribosomes, smooth doesn’t.

Vesicles

Floating sacs that transport materials in, out, and around the cell. May originate from Endoplasmic Reticulum

Gogli Apparatus

Takes material from the ER and modifies them and send them out in a vesicle for transport around the cell

Mitochondria

Site of cellular respiration. Produces ATP from sugar which the body uses for energy

Lysosome

Found only in animals. Specialized vesicles that have digestive enzymes

Vacuole

Found in both plants and animals but are larger in a plant cell. Storage for water, food, and minerals

Centrioles

Found only in animal cells. Responsible for the division of genetic material during mitosis. 

Chloroplast

Turns light energy into glucose (photosynthesis). Only in plant cells

Cell well

Rigid outer structure of plant cells. Composed of cellulose (fibre)

Phospholipid bilayers

Make up the cell membrane. Have a hydrophilic head and hydrophobic tail

Brownian motion

Random motion due to the kinetic energy of a fluid. Causes diffusion.

Equilibrium

Equally distributed molecules

Three types of passive transport

Diffusion, Osmosis, and Facilitated Diffusion

Diffusion

Passive movement of solutes from a high concentration to a low concentration

Osmosis

The diffusion of a liquid across a membrane. Goes from a low concentration of solutes  to a high concentration of solutes. (this is still high to low concentration of the liquid itself).

Direction of osmosis

Hypotonic to hypertonic

Hypotonic

Less concentration of solutes then the fluid across the membrane

Hypertonic

Greater concentration of solutes than the fluid across the membrane

Isotonic

Equal concentration of solutes as the fluid across the membrane

Fluid Mosaic Model

A model of the cell membrane as a non-rigid structure where parts move fluidly past each other

Roles of embedded proteins

• Move larger or polar substances across the membrane

• Act as marker molecules to allow cells to recognize each other

• Attachment sites for hormones and messenger molecules

Facilitated Diffusion

A form of passive transport where diffusion happens across a transport protein. Goes from high concentration to low concentration.

Channel Protein

A transport protein that only does passive transport (facilitated diffusion). Act like tunnels for larger or polar molecules

Carrier protein

A transport protein that can do active or passive transport. Act like locks and keys for specific chemicals

Active transport

Transport that requires ATP energy. Goes against the concentration gradient.

Endocytosis

A form of active transport where a cell engulfs a chemical pinching it off into a vesicle

Exocytosis

A form of active transport where a vesicle embeds itself into the membrane and then releases its content 

receptor-mediated endocytosis

Endocytosis but with a protein that detects specific chemicals

Phagocytosis

Endocytosis with solids

Pinocytosis

Endocytosis with fluids