Plant and Animal Cells

• Living things complete life processes denoted by "MRS GREN" and are made of at least one cell.
• Cells enable life processes like photosynthesis (nutrition), respiration (energy), and cell division (growth and reproduction).

Animal Cells

• Do not have a cell wall or chloroplasts, and cannot make their own glucose.
• Multicellular, complex animals have four primary tissue types that include epithelial, connective, muscle, and nervous.

Plant Cell Organelles

• Mitochondria is the location where aerobic respiration takes place with smooth outer and wrinkled inner membranes called cristae.
• Plasma (cell) membrane is a thin, flexible layer around the cell separating the cytoplasm from its surroundings and regulates what enters and exits.
• Cytoplasm is a jelly-like fluid where cellular reactions occur, and support the cell.
• Vacuole involves membrane-bound compartments for secretion, excretion, and storage.
• Ribosomes are the site of protein synthesis that floats in the cytoplasm or associated with the endoplasmic reticulum.
• Lysosome contains digestive enzymes to digest old cell organelles and parts of organelles.
• Nucleus regulates all cell activity and containing the cell's DNA genetic material
• Nucleolus is a bounded structure inside the nucleus that transcribes ribosomal RNA (rRNA) and assembles it within the cell.
• Golgi body is near the endoplasmic reticulum that modifies, sorts, and packages proteins from it for storage and transport.
• Endoplasmic Reticulum (ER) creates a plumbing network throughout the cell, works with the Golgi body and ribosomes, and can be smooth (no ribosomes) or rough (ribosomes present).
• Vesicle involves a unique enclosed space involved in transport, secretion, and excretion.

Plant Cells Distinctives

• Have a cell wall providing structure.
• Contain chloroplasts, enabling them to produce glucose through photosynthesis.
• Store water in a large vacuole for structure and photosynthesis.
• Cell Wall is a semi-rigid cellulose layer outside the cell providing support.
• Scratch Granule involves stored carbohydrate scratch in plastids.
• Large Central Vacuole serves a variety of secretory, excretory, and storage functions.

The Cell Membrane

• All cells have a membrane separating them from the outside determining what enters and exits
• Composed by a thin, flexible barrier protecting the cell and regulating substance passage.
• Structure is a double-layered ("bilayer") of phospholipids with embedded proteins allowing selective substance passage.
• Some substances like water (via osmosis), oxygen, and carbon dioxide can travel directly through the phospholipid bilayer

Cell Membrane Models

• Fluid Mosaic Model involves describing the membrane as fluid because phospholipids/proteins aren't fixed.
• “Mosaic” nature involves proteins and embedded substances that are randomly scattered in the matrix.
• Some molecules move down a concentration gradient through simple diffusion, facilitated diffusion or osmosis

Photosynthesis

• Plants use small chemical compounds and light energy to produce food (glucose).
• Conversions: light energy to glucose, glucose to ATP (usable energy), which completes life processes and manufactures cellulose.

Photosynthesis Reactants

• Light energy absorption occurs by chlorophyll inside chloroplasts.
• Carbon dioxide enters via stomata and diffuses through the leaf.
• Water is absorbed by roots, travels up the xylem, and enters the chloroplast.

Inside the Leaf Adaptations

• Specialized cross-section structures maximize light capture, carbon dioxide intake, and water management.
• Waxy cuticle: Clear layer seals the leaf, prevents water loss, and allows light to be absorbed.
• Upper epidermis functions by a protective layer that is transparent allowing light to pass through.
• Palisade mesophyll is tightly packed and are full of chloroplasts.
• Spongy mesophyll loosely arranges cells to allow carbon dioxide to reach all cells.
• Guard cells open and close stomata to prevent excess water loss.
• Gas exchange occurs by passive diffusion from high to low concentration.
• Stomata is small openings that regulate the intake of CO2 and output of O2.
• Essential organelles which maximize this process via a thin semi-permeable membrane for light penetration.
• Thylakoids stacked into grana containing chlorophyll increasing surface area for light absorption.
• Grana connected by lamellae to facilitate chlorophyll movement.
• Stroma is a matrix where lamellae and grana are suspended, allowing sunlight to penetrate.
• Chloroplasts are in cells of green plants/algae abundant in cells near the top of leaves.
• Chlorophyll absorbs sunlight for photosynthesis which uses (CO2) and water (H2O) to form glucose, and releases oxygen (O2).
• Chloroplast structure maximizes photosynthesis with a semi-permeable membrane, thylakoids, grana, lamellae, and stroma

Chlorophyll Functions

• Molecules capture sunlight causing it to to enter a higher energy state with LIGHT-DEPENDENT reactions.
• Light-dependent reactions happen in thylakoid membranes uses sunlight to split water into hydrogen and oxygen. ATP is also produced.
• ATP: energy currency molecule for cells; a phosphate group is added to an existing ADP molecule,
• This allows light-independent reactions to combine hydrogens with carbon dioxide to form glucose (C6H12O6) via special hydrogen-carrier molecules transport.
• ATP from the LDR provides the energy which then returns to the thylakoids to pick up more energy and hydrogens.
• Calvin Cycle reactions don't use light directly depending on products of the light-dependent reactions.

Factors Affecting Photosynthesis

• Physical and biological factors affecting Rate of Photosynthesis (ROP) that includes CO2/water availability, light intensity/wavelength, chlorophyll molecules, and trace nutrients.
• Increased in these factors generally increase the rate of photosynthesis (ROP) will increase until another factor is lacking/short supply.
• Light intensity affects the rate as light energy drives the making of the chemical energy (glucose+oxygen)
• Chlorophyll is needed to absorb any light energy where saturating light leads to another limiting factor.
• Carbon dioxide is used with oxygen in CO2 to create a glucose molecule (C6H12O6)
• Plants prevent water loss which splits in the light dependent phase producing hydrogens for the glucose molecule (C6H12O6)
• Enzymes which controls photosynthesis are temperature sensitive that requires the reactants collide with enough energy that slows if too cold.

Photosynthesis Results

• The process will decrease as essential enzymes begin to denature and change shape
• Color affects photosynthesis becaus green is most reflected/provides the least for the light-dependent reaction, which has less split water and is unavailable to join with carbon dioxide
• Chlorophyll uses the plant's need for Magnesium & Phosphorus to form enzymes & Potassium to activate them.

Enzymes Effects

• If the ROP is low due to an additional limiting reaction or it slows down when cold / quick loss when hot it is critical to note why on exams.
• Essential for Cells that converts sugars (glucose) into ATP through cellular respiration in virtually every cell.
• Each has two membranes (smooth outer and folded inner) with cristae increasing surface area for energy production.

Respiration & ATP

• Why an organism respires: Life processes need chemical energy while plants makes glucose, animals eat organic molecules, but cells use ATP, not glucose, for energy.
• Allows respiration to converts glucose into ATP and by-product.
• Can be aerobic (uses oxygen, is preferable) or anaerobic (doesn't use oxygen).
• ATP in the usable energy form can be created through the process of adding a phosphate group is added to an existing ADP molecule.
• Mitochondria structure (long and thin) supports ATP production by increasing surface area for molecule transport.
• Consists a double membrane that is outer is simple & semi-permeable for letting molecules cross in and out.
• Next pyruvate (halved glucose) will enter for aerobic respiration where pyruvate is then converted to acetyl-CoA.
• Matrix is fluid-filled space where enzymes catalyse Krebs Cycle reactions
• Krebs Cycle involved: acetyl-CoA broken down to produce small, high-energy molecules carrying electrons for ATP inside.
• Inner Structure with folding forms the cristae for energy production containing embedded proteins/enzymes for the ATP producing electron transport chain
• The increasing in folding allows greater molecules to allow a greater ATP mass production
• Involve glucose being halved into pyruvate and crossing membrane to produce ATP.
• Enzymes catalyse reactions using acetyl-CoA from pyruvate to make small, high energy molecules with Location using liquid matrix.
• Electron Transport Chain: converts these molecules to produce ATP in Cristae
• Mitochondria occurs involving aerobic respiration with oxygen while the production of glycolysis uses the cytoplasm.
• Glucose is halved into pyruvate in the cytoplasm using little amount of ATP
• Pyruvate travels to the mitochondria undergoing multiple reaction which requires oxygen to result in ATP and it's by-products.

Anaerobic and Aerobic Respiration.

• Anaerobic respiration does not use the involvement of mitochondria uses ATP that makes lactic acid.
• Involve Aerobic Glycolysis where Glucose being broken down into two pyruvate molecules to produce ATP.
• Pyruvate enters mitochondrial matrix and is reacted creating by-product of ATP
• the electrons adds phosphate to create high levels of ATP in cristae.
• Anaerobic respiration is used in low-oxygen environments, with a quick process of glucose broken done into pyruvates. This process in animal cells makes dangerous lactic acid and thus unsustainable.
• Aerobic respiration is preferred making ATP and nothing toxic whereas anaerobic will not distribute oxygen and creates the build-up of lactic acid that could be toxic.

ATP:

• ATP uses Protein synthesis, cell division, muscle contraction, cell signalling & transport across membranes.
• reactions requires chemicals that enter/exit cells, and cell transport (moving substances across the cell membrane) occurs.
• Mitochondria and chloroplasts are rod shaped to increase their surface area where the higher the better.
• This ensures cells absorb substances (nutrients, H2o, O2) that is dependent on diffusion that is a major limited factor in setting the size.
• Broad classification determines the cell membrane as either active transport, passive transport.

Cell transport

• Cells move to reach an equilibrium where the cell gradients are equal on both sides leading to an active transport using ATP.
• Passive transport moves along the concentration gradient, including:
  • simple diffusion that allows the molecules DIRECTLY cross through
  • E.g. oxygen, carbon dioxide
  • osmosis allows the water diffusion across the membrane. -Facilitated diffusion uses special proteins allowing diffusion through
• Solutes can pass if uncharged and small (carbon dioxide/oxygen) through the membrane.
• Large or charged particles needs proteins such as glutose or amino acids through proteins to move
• Specific carriers move through that react to the various temperatures that occur and will become toxic.

Osmosis

• Osmosis is the water's movement through semipermeable membranes at various concentrations.
• Water spreads from low to high to make the solute spread out and always passive.
• Osmosis balances the water using water absorption/regulation that prevents dehydration and occurs until equilibrium.
• Solutes will have little water and space meaning more will be less for osmosis.
• Hypertonic has greater solute and no water vs hypotonic that is opposite
• osmosis occurs from the high water concentration to the low water concentration when reaching equilibrium.

Effects

• Hypertonic result water diffusing out.
• Hypotonic result water diffusing in causing it to bust.
• Hypertonic result plants to shrivel called plasmolysis vs hypotonic is ideal for structure because it remains firm and swollen.
• Bulk quantities/large transports that need ATP are defined as active transport that move in bulk.
• It moves to rearrange the cell membrane to change it's shape to engulf nutrients and minerals which pump again gradients to keep the process flowing.
• Enzymes allows the chemical process to occur faster with an active site ready to bond specific molecules used and reused in biological processes.
• Enzymes are special proteins crucial for life that work by lowering energy
• Reaction rates are based on the molecule contact involved.
• Bonding will change shapes affecting it's activity.
• Affecting factors are caused by a specific spot to link to that substrate and change the activity leading to a breaking or adding
• Act as catalysts increasing processes like reaction rates to form a certain shape and is induced until a different reaction starts

Enzymes Processes

• Key and lock where the substrate does not change and an induce process where the substrate change and forms a better fit
• The shape of the structure has a close fit but need it altered and altered substrates change it to then revert it after reaction.
• Involve bondings that affect reaction rates especially surface area
• Higher concetrations allow greater collisions
• Temperature is crucial for catalysis and a rise lowers or breaks the chemical bond
• pH levels and ions is crucial otherwise the chains will alter making enzymes unable to do thier task

DNA Structure

• Uses DNA (Deoxyribonucleic Acid) that carries genes in a double helix unit called nucleotide.
• Genes are passed from offspring and must divide beforehand to grow.
• A blueprint that contains four nitrogenous bases; Adenine(A), Thymine, Gunanine and Cytosine(C) linking specifically to form a rung and replicate.
• They are separated with semi conservative results in two new copies with one from the old

DNA Replication

• The template travels 3 to 5 and runs antiparallel and build to 5' to 3 or new nucleotides.
• An enzyme called DNA polymerase assists and new base pairs can be read that form the leading strand that form the new molecules
• As the the helicase unzips dna the DNA strand can't be right away and takes time to get cut and form new parts

The Cell Cycle

• This forms the lagging strand as it waits and unzips parts
• It takes new DNA copies that unwind to unzip DNA with enzyme called Helicase traveling 5' to 3 and read backwards
• Semi conservatie has enzyme helicase to unzip DNA is reversed but enzyme must bind at the front.
• DNA will continue to be made to increase for the next time which occur during the various stages

The Cell Cycle Stages

• Interphse to preform division to repair tissues in a controlled manner
• There is a larger surface area coming from new cells in a process called mitosis
• First phase sees cell growth, then later DNA is replicated, further processes occur and then winds into chromosomes to divide.
• Interphase has the cell prepare for mitosis
• Prophase: cell condenses and super coils for chromatids that disappear
• Metaphase creates aligned chromosomes, while anaphase sees chromosomes torn apart
• Telophase retracts the chromosome and turns the coilings off splitting through cytokinesis to become 2 cells
• Nutrients and energy allows for replication to be easier that stops as lacking from malnutrition and cells like bone marrow need these
• Growth and maintenance is reliant on the enzyme and replication that can be affected by external sources otherwise damage and death occur.