Characteristics of Living Organisms

• Eight life processes are summarized as MRS H GREN.
• Movement means the ability to change position, seen as muscle actions in animals and slow growth movement in plants.
• Respiration involves chemical reactions in cells, breaking down molecules for metabolism energy.
• Sensitivity means responding to surroundings, such as detecting internal and external changes, and carrying out appropriate responses.
• Homeostasis involves maintaining a steady internal environment and controlling internal conditions to maintain a steady state.
• Growth and Development involves an increase in size and complexity.
• Growth is a permanent increase in size and dry mass, through cell number or cell size increase.
• Development increases complexity.
• Reproduction is the ability to produce offspring, making more of the same kind of organism.
• Excretion means removing waste products, toxic materials, excess substances, and metabolic waste products.
• Nutrition is requiring and acquiring nutrition, taking in nutrients for energy, growth, and repair.

Variety of Living Organisms

• Cells are either prokaryotic or eukaryotic.

Eukaryotes

• Eukaryotic cells have a nucleus, cytoplasm, plasma membrane, and membrane-bound organelles.
• These cells can be unicellular or multicellular.

Plants

• Plants are multicellular, with cell sizes ranging from 10 to 100 μm
• Plant cell structures include a cell membrane, cell wall, chloroplast, endoplasmic reticulum, nucleus, mitochondrion, permanent vacuole, and cytoplasm.
• Nutrition in plants is autotrophic, through photosynthesis
• They store carbohydrates as starch or sucrose
• Examples include flowering plants like maize and herbaceous legumes like peas.

Animals

• Animals are multicellular, with cell sizes ranging from 10 to 100 μm
• Animal cell structures include cell membrane, cytoplasm, mitochondrion, nucleus, Golgi body, and lysosomes.
• Animal nutrition is heterotrophic, consuming other organisms
• They store carbohydrates as glycogen and possess nervous coordination
• Examples include mammals and insects

Fungi

• Fungi can be unicellular (2-5 μm) or multicellular (10-100 μm).
• Fungal structures include chitin cell wall, vacuole, nucleus, cell surface membrane, and cytoplasm
• They form mycelium from hyphae, where the hyphae have many nuclei
• Reproductive structures include mushrooms and toadstools
• Spores land on food, hyphae grow and branch, then mycelium covers the surface.
• Fungi can be saprotrophic, consuming dead organisms, or parasitic, consuming living organisms using extracellular digestive enzymes and absorption.
• They store carbohydrates as glycogen
• Examples include Mucor, Yeast, and pathogenic fungi like Athlete's foot.

Protoctists

• Protoctists can be only unicellular
• Protoctist structures include a nucleus, ribosomes, cell membrane, mitochondrion, cytoplasm, and contractile vacuole
• Nutrition can be animal-like or plant-like
• Animal-like examples include Amoeba which live in water
• Plant-like examples include Chlorella, that have chloroplasts
• Pathogenic examples include Plasmodium, causing malaria

Prokaryotes

• Prokaryotic cells have no nucleus or membrane-bound organelles.
• Prokaryotic cells are only unicellular.

Bacteria

• Bacteria are unicellular, with cell sizes ranging from 1 to 5μm.
• Structure includes slime capsule, peptidoglycan cell wall, Cell membrane, Flagella
• They have cytoplasm, and a nucleoid consisting of a loop of DNA chromosome
• Plasmids, which are rings of DNA, replicate and move info through cells to share info and consist of rods, spherical or spiral shape
• Pathogenic bacteria release toxins
• Nutrition can be autotrophic, through photosynthesis or heterotrophic, consuming other organisms
• Examples include rod-shaped Lactobacillus bulgaricus that makes yoghurt or Salmonella that causes food poisoning, and spherical-shaped Pneumococcus that causes pneumonia.

Pathogens

• Pathogens are anything that produces disease, and include fungi, bacteria, protoctists, and viruses.

Viruses

• Viruses are non-living microscopic particles, sized from 0.01 to 0.1μm
• Viruses do not have a cell structure, but have an envelope from the host's membrane, a protein coat and DNA/RNA
• Viruses are parasitic and reproduce inside living cells by hijacking the cell mechanisms
• It then creates millions of copies of itself then spreading by cell bursting
• Examples include Tobacco mosaic virus, Influenza virus and HIV virus

Levels of Organization

• The levels of organization are: Organelles → Cells → Tissues → Organs → Organ systems → Organisms.
• Organelles are membrane-bound subcellular structures, for example, ribosomes, and are found in the cytoplasm.
• Cells are the basic functional unit of all living organisms, for example: a red blood cell and contains organelles.
• Tissues are a group of similar cells carrying out specific functions, such as muscular tissue and are only made up of one type of cell.
• Organs are a group of similar tissues carrying out a specific function, for example, the stomach
• An organ system consists of several different organs working together, for example, the endocrine system
• Digestive system digests food and absorbs digested materials
• Gas exchange exchanges of CO2 and O2
• Circulatory system transports materials
• Excretory system removes toxic waste materials
• Nervous system coordinate the body's actions
• Endocrine system consists of glands secreting hormones.
• Reproductive system is responsible for the production of eggs/sperms and development of embryo.
• Organism is individual plant, animal or single celled life form.

Cell Structure

• Organelles are subcellular structures in cells
• Cytoplasm is where chemical reactions take place, it is living, jelly-like material that supports organelles and contains enzymes, water and solutes

Nucleus

• Nucleus contains genetic information of a cell
• Enclosed in a nuclear membrane, contains chromosomes
• It Controls cell activity by determining proteins produced, and where DNA remains in the nucleus and carries instructions to the cytoplasm for proteins to be made

Cell membrane

• Selectively permeable layer that controls entries and exits.
• Forming boundary with outside and helps stay together
• Selectively controls substances.

Mitochondria

• Mitochondria involves site of cellular respiration

Ribosomes

• Ribosomes involves site of protein synthesis
• It is within cytoplasm or attached to membranes

Cell Wall

• Cell walls are made of Non-living cellulose that protects cells.
• It is a freely permeable layer outside cell giving support
• Internally adds support which pushes to keep plants in shape

Chloroplasts

• Site of photosynthesis in plant and absorbs energy

Vacuole

• Large storage vesicles.
• Which contain cell sap
• Improves ridigity by filling the cells and swelling with water

Similarities and differences between plant and animal cells

• **Di erences Plant cells vs Animal cells
• Plant cells contains no nervous coordination , but animal cells does
• Plant's carbs contains starch + sucrose , animal cells glucose + glycogen
• Plant cells are Autotrophic , animal cells are Heterotrophic
• Plants cell contains more structures such as cell walls, chloroplasts, vacuole, but animals does not
• Plants with fixed shaped, animals no fixed shape
• **Similarities Plant cells vs Animal cells
• Carries out eukaryotes
• Has membrane bound organelles
• Carries out respiration.

Cell Differentiation

• Differentiation of cell is the development of new subcellular structures
• This allows for cells to performs specific functions

Mitosis

• Mitosis is the cell division that result in two genetically identical cells
• Zygotes divides by mitosis and grows
• Differentiation happens when embryo grows by cells become specialized and adapted to roles

Differentiation in plants / animals

• Plants can differentiate throughout its life and make new tissue
• Animals cells differentiate early on in development and mature cells don't divide often.

Specialised Cells

Specialised cells are cells that have developed characteristics for particular functions. Red blood cell Adaptation Has haemoglobin for carrying oxygen., thin and concave, no or nucleus

Ciliated epithelial cell Adaptation Layer of hair-like cilia that moves due to the many mitochondria Sperm Cells Adaptation Contains enzymes inside its head to penetrate egg, mitochondria and long tail for speed

Leukocyte cells Adaptation Can move through walls and infections

Adaptation Can send electric signal through long range with insulated axons

Stem cells

• Underierntiated + unspecialized and able to deifnetiate
• Can be embryonic, adult, or meristmes

Embryonic stem cells

• Can from all kinds of stem cells
• Can be cloned by culturing it and directed to differentiate

Adult stem cells

• Can from specialized tissued
• Lost ability can can no longer differentiate

Meristems

• Differentate to any plant
• Can clone, and help plants near extinction

Use of Stem cells

• Stem cells are for development of development, growth, repair
• Replacing damaged cell
• Burn treatment, attirts, replacement

Therapeutic

• Replicates from embrytos using dNA
• Won't be rejected

Stem cell therapy

• Used to treet decease

Bene ts and Issues

Ethical to use Might mutate, hard to find cell, could transmit disease

Biological molecules

• Many monosaccharises joined together which function as energy
• Mono -> di -> poly
• Chain of amino acids where function is growth and repair and function with enzymes
• Amino -> peptide -> protein
• Fatty acid with glycerol which function to make membranes and energy

Carbon Hydrogen Oxygen

All contain Testing food Add iodine: strach will yellow / black Add Benedict: glucose well need heat and will green/red

Add biuret: shake for purple protein Add ethanol: whipe and hazy Add sundan: red layer on surface

Enzymes

• Biological catalysts that speed action without using up
• Provide allternitive path of reaction

Lock and key hypothesic

• Active area of enzymes are specific to substrates and attach to them

• Form enzymes-substrate

• Becomes product of reaction

Factors afftecting enzymes

Speed up if enzyme, faster if substrate present Temperature: must be optimal Above that temp then becomes denaturarized Ph must be at optimal levels or also becomes denaturized Practical Starch/ amylase or just heated or placed in buffer

• Every minute add drop and watch color of chemical turn black
• time taken will determine rate

Movement of Substances

• Diffusion moves particles in high concentraion to low concertraion levels
• Passive and no energy involved
• Difference in concentrated in rate is determined

Osmosis

• Diffusion of water molecules that transfer and has high concentration to low
• 3 ways it moves
• Tonic- all levels are equal
• Hyper moves with with high solutes
• Hypo moves with low

Active transort

• Moves low to high
• Uses energy

water travels easy in distilled water high potato level

Nutrients for plants

carbon dioxide+water makes glucose + oxygen formula needs energy

Leaf structur

Surface are for maximum absorbtion Chlorphyl allows for light Structure of vascular bundles - moves water Cutile- thing protective layer upper epi- allow light pailsade meso- pack with chloro spongy- air in meso to move gases lower epi - contains guard cell and storm

Water gaurd cell- close and ands storm

• storm - gas exchange

Mineral for food

Mag - turn green to yellow Niti- stunts growth K- dots on cells.

Protical Photosynntheis

• Lower carbon means higher process of photosynthesis , change colors of solution in tubes

Prodcut

• Storred in strach Lighter only founds in areas where cholorphyl grows Put leaves is jar for co2 destract put in dark store to starc