year 11 bio.docx

Modern cell theory

The cell is the smallest living unit in all organisms, all living things are made up of cells, and all cells come from pre-existing cells.

3 Domains of life

Bacteria, Archaea, Eukarya.

Eukarya

Domain that includes organisms such as protists, plants, animals, and fungi.

Multicellular

Consisting of many cells.

Unicellular

Consisting of a single cell.

Prokaryotes

Organisms that are unicellular and have no membrane-bound organelles.

Bacteria

A group of prokaryotic organisms found in diverse environments.

Archaea

A group of prokaryotic organisms found in extreme and harsh environments.

Eukaryotes

Organisms with a true nucleus and membrane-bound organelles, can be unicellular or multicellular.

Cell membrane

A structure that protects a cell and regulates what enters and exits.

Ribosomes

Cellular structures where protein synthesis occurs.

Mitochondria

The powerhouse of the cell, responsible for energy conversion.

Chloroplast

An organelle that contains chlorophyll and is involved in photosynthesis.

Fluid Mosaic Model

Describes the structure of cell membranes as a mosaic of various components.

Natural selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Selection pressure

External factors that affect an organism's ability to survive in a given environment.

Microevolution

Evolutionary change within a population over a short period of time. creates new breeds of a species

Macroevolution

Evolutionary change that results in the emergence of new species over long time periods. Creates new species

DNA Hybridisation

A technique to measure genetic similarity between different species based on DNA strand compatibility.

1. A piece of dna is isolated from each organism 

2. Multiple copies of each gene are made, using fluorescent dyes to distinguish the four bases in DNA 

3. Computer linked equipment called a DNA SEQUENCER is used to graph and print out the entire sequences of bases, which are then compared

Comparative anatomy

The study of similarities and differences in the structure of organisms to infer evolutionary relationships.

All mammals share the same arrangement of bones in their forelimb

• Humorous

• Radius

• Ulna

• Carpals

• Metacarpals

• Phalanges

Biogeography

The study of the geographical distribution of living organisms and the historical processes that affected their distribution.

Relative dating

A method of determining the age of fossils by comparing their placement with that of similar fossils.

Absolute dating

A method that determines the precise age of fossils through techniques such as radiometric dating.

Nucleus - Function

The control center of the cell, holding DNA material; often referred to as the 'brain' of the cell.

Nucleus - Structure

Spherical shape, enclosed in a double membrane. Contains chromatin (DNA), which organizes into rod-shaped chromosomes.

Nucleoli

Inside the nucleus, containing high concentrations of RNA (a close relative of DNA), important for ribosome manufacture used in protein synthesis.

RNA

This is a single-stranded nucleic acid consisting of nucleotides (C, A, G, U).

Nuclear envelope

This double membrane protects genetic material by separating the cell's DNA from the rest of the cell.

Mitochondria - Function

The powerhouse of the cell - plays an important role in cell respiration and converting energy from glucose into energy used by cells.

Mitochondria - Structure

Has an outer membrane and a highly folded inner membrane (cristae) which increases the surface area whereby the reactions occur. Contains its own DNA and ribosomes.

Matrix

Viscous, gel-like space within the mitochondria that contains a variety of enzymes, ribosomes, mitochondrial DNA, and other molecules necessary for cellular respiration.

Granules

Composed of calcium, magnesium, and various proteins found in the mitochondria.

Outer membrane

Protects the organelle, allowing only certain substances (small proteins) to pass through. Contains small particles that aid the flow of nutrients.

Cristae

The inner membrane folds in the mitochondria that increase the surface area for ATP production.

Chloroplast - Function

They contain a green pigment called chlorophyll that is vital for carrying out photosynthesis.

Chloroplast - Structure

Can be seen through a light microscope; surrounded by a double membrane with internal membranes arranged in stacks (grana) for photosynthesis. Contains its own DNA.

Granum

Stacks of thylakoid found in the chloroplast; increases surface area where photosynthesis reactions occur

Stroma

The liquid background of the chloroplast.

Ribosomes - Function

Site where protein production occurs.

Ribosomes - Structure

Not enclosed by a membrane; may be attached to the endoplasmic reticulum. Contains protein and RNA.

Endoplasmic reticulum - Function

Transport of substances within the cells occurs through this system of channels.

Endoplasmic reticulum - Structure

A system of channels in a cell, formed by membranes.

Smooth endoplasmic reticulum

Has no ribosomes and appears smooth; involved in the production of enzymes (lipids, fats, hormones) that assist with making sex hormones.

Rough endoplasmic reticulum

Contains ribosomes on its surface, making it appear rough. Site of protein synthesis. Transports proteins produced by ribosomes into the golgi apparatus.

Golgi apparatus - Function

Sorts, stores, and dispatches the products of cell metabolism (proteins).

Golgi apparatus - Structure

Several layers of membranes that package material into membrane-bound bags or vesicles for export. These vesicles carry the material out of the cell.

Vesicle

Transports substances in and out of the cell.

Vacuole

Store substances that aren't immediately needed.

Cisternae

Has enzymes that modify proteins.

Phospholipids

Forms the basic structure of the cell membrane (phospholipid bilayer) which is semi permeable.

Phosphate head

Water attracting part of phospholipid and faces outward toward water because it is polar and hydrophilic

Fatty acid tails

Water repelling part of the phospholipid and faces inward toward water.

Cholesterol

Maintains the membrane stability, ensuring membrane is firm but flexible

Glycoprotein

A protein with a carbohydrate chain attached – used for cell recognition, communication, and immune response. Acts like a cell ‘name tag’ that helps cells identify each other. Chains attach to proteins acting like name tags for all cell recognition and communication so we can recognise the substances that move in (substances that can be used) and out (waste)

Peripheral protein

Sits on the surface of the membrane. Helps with cell signalling support or anchoring of other structures. Signal hormones help give cell shape and support, anchoring integral proteins.

Acts like a pore – allows specific substances like ions

Lysosomes - Function

They release enzymes and cause cell death. Proteins, fats, and polysaccharides are no longer needed by the cell and are broken down. Cell’s recycling centre or waste disposal system. Gets rid of cells infected with pathogens in a way where it can be restored and reused again.

Lysosomes - Structure

Sacs of enzymes enclosed by a membrane

Vacuole - Function

Stores water and food for cells and waste (CO_2)

Vacuole - Structure

Membrane-bound spaces that are smaller in animal cells, and larger in plant cells. Larger in plant

Plant Cell Characteristics

Contains chloroplasts for photosynthesis, has a cell wall for structural support, and a large central vacuole for storing water and nutrients.

Plant Cell: Cell Wall

A rigid outer layer made of cellulose that provides support and protection to the cell.

Plant Cell: Chloroplasts

Organelles containing chlorophyll where photosynthesis occurs, converting light energy into chemical energy.

Animal Cell Characteristics

Lacks a cell wall and chloroplasts, has smaller vacuoles, and possesses centrioles important for cell division.

Plant vs. Animal Cells

Plant cells have a cell wall and chloroplasts, animal cells do not. Animal cells have centrioles, plant cells do not. Vacuoles are larger in plant cells than in animal cells.

Photosynthesis equation

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O

Cellular respiration equation

C₆H₁₂O₆ + 6O → 6CO₂ + 6H₂O<

Nuclear pore

Series of openings in the cell’s nucleus membrane that acts as a channel of transport to the cytoplasm. Transports proteins, RNA, and other molecules.

Nucleoplasm

Gel-like substance that fills nucleus of a cell.