Biology

• The cell membrane is a selectively permeable barrier that surrounds the cell and regulates the movement of substances in and out of the cell.
• Semi-permeable


  Allows the entry and exit of smaller, non-polar molecules but does not allow larger, polar molecules to pass
• Polar molecules


  Molecules with an uneven distribution of charge
• Amylase


  An enzyme that hydrolyses starch into sugar
• Diffusion is passive and does not require energy (ATP)
• Plant cells


  Cells that have a cell membrane, cytoplasm, mitochondria, ribosomes, vectors, endoplasmic reticulum, and Golgi apparatus
• Cell membrane


  Controls the entry and exit of materials into the cell
• Cytoplasm


  The nutrient-rich fluid in which other organelles are found
• Mitochondria


  Provides energy for the cell
• Ribosomes


  Makes proteins
• nucleus

  Controls and regulates the cell, DNA is found in the nucleus
• Endoplasmic reticulum


  Transports proteins and other substances
• Golgi apparatus


  Folds and packages proteins and sends them to their correct location
• cellular respiration


  breaking down glucose to be used in the cell
• Photosynthesis


  making glucose- carbon dioxide and sunlight -> oxygen + glucose + energy
• vacuole:

  Storage for nutrients and substances

  Plant: Store nutrients and participate in cellular processes.
• Ribosome:

  Responsible for protein synthesis, They read the signals mRNA and Facilitate the assembly of amino acids into polypeptide chains, forming proteins.
• Cytoskeleton:

  →components: Include microfilaments, microtubutes, and intermediate filaments.

  → Function: Provides structural support, maintains cell

  shape, Facilitates intracellular transport, and is involved in cell mobility.
• Cell membrane (plasma membrane):

  → Function: The cell membrane regulates the passage of

  substances in and out of the cell, provides structural support, and plays a role in cell communication.
• Lysosomes:

  → Function: Lysosomes contain enzymes that break down

  and digest cellular waste, old organelles, and foreign substances. They play a crucial role in cellar recycling and maintaining cellular homeostasis.
• Golgi apparatus


  Folds and packages proteins and sends them to their correct location
• Osmosis


  spontaneous net movement of water molecules across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.
• Diffusion


  Its a spontaneous net movement of particles from an area of high concentration to an area of low concentration.
• Osmosis 


  crucial for distributing nutrients and removing metabolic waste products, and also for the absorbtion of water by plant roots.
• Factors that affect enzyme activity

  pH, temperature, substrate concentration, enzyme concentration
• Enzymes are proteins comprised of amino acids linked together in one or more polypeptide chains.
• Catalyst


  Substances that change the rate of reaction without being used up or broken down in the reaction.
• How do catalysts work?

  they provide an alternative route for the reaction with a lower activation energy
• What are enzymes?


  Proteins that are capable of catalysing biochemical reactions they are therefore called biological catalysts.
• What do enzymes do?

  They lower the energy required for a reaction to preceed, therefore speeding up the reaction.
• Anabolic pathways


  Build complex molecules from simpler ones and typically need and input of energy. Building glucose from carbon dioxide is an example.
• Aerobic respiration


  creates ATP (energy)
• label the plant cell organelles

  A) cell wall

  B) Mitochondira

  C) large vacuole

  D) cytoplasm

  E) cell membrane

  F) chloroplast

  G) nucleolus

  H) nucleus

  
• Label each organelle in the animal cell

  ve

  A) centrosome

  B) cytoplasm

  C) Rough ER

  D) Smooth ER

  E) Ribosomes

  F) golgi body

  G) mitochondrion

  H) vacuole

  I) nuclear membrane

  J) nucleolus

  K) nucleus

  L) lysosome

  M) cell membrane

  
• hypertonic

  solution has a higher solute concentration compared to the intracellular solute concentration
• hypotonic solution

  is any external solution that has a low solute concentration and high water concentration compared to body fluids
• isotonic


  Same concentration on outside and inside
• Anabolism

  The building of complex molecules from numerous simple ones.
• Catabolism

  The breaking down of complex molecules into numerous simpler ones
• No nucleus?

  prokaryotic