Cells, Tissues and Organs

Animal Cells:

• Nucleus: Contains DNA and controls the cell
• Cell Membrane: Controls what goes in and out of the cell
• Cytoplasm: Where chemical reactions take place
• Ribosomes: Synthesize proteins
• Mitochondria: Release energy

Plant Cells (All of the above and):

• Cell Wall: A rigid shell to help the cell keep its shape
• Vacoule: Pushes the middle of the cell 'outwards' to help keep the cell rigid
• Chloroplasts: Absorb light energy which is used for photosynthesis

Prokaryotic Cells:

• The name for (all of) the group of bacterial cells that are vital to life on earth
• Always single celled organisms
• Reproduce by asexual reproduction
• Much smaller than eukaryotic cells
• No nucleus or mitochondria

Eukaryotic Cells:

• The name for all animal and plant cells, algae and fungi

• Specialised Cell: A cell that has a specific or particular job/ function
• Differentation: When a normal cell becomes a specialised cell
• Neurone: Send impulses aroud the body
• Root Hair cell: Absorb water and nutrients form soil
• Red Blood Cells: Carries oxygen around the body, contains haemoglobin (attatches to oxygen to transport it) , small to fit through capillaries 

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• Diffusion: The random movement of particles in the air, moving form an area with high concentration to low concentration

Factors affecting Diffusion:

• Surface area: Volume
• Diffusion distance
• Temperature
• Concentration distance

Tissues:

• A group of cells with similar structures and functions working together
• Muscle tissue can control movement
• Glandular tissue can produce enzymes and hormones
• Mesophyll tissue contains chloroplasts

Organs:

• Organs are made up of tissues
• The stomach is an organ containing:
  • Muscle tissue to churn food
  • Glandular tissue to break down food
  • Epithelial tissue which covers the inside and outside of the organ
• The pancreas makes hormones tht control blood sugar and digest food

Organs in a Plant:

• Flower: Reproduce
• Leaf: Photosynthesis (Absorb light)
• Root: Absorb water and nutrients, stablises the plant
• Stem: Carry water to the leaves, supports the plant
• Fruit: Casing for the seed

Leaf structure:

• Waxy cuticle: Keeps water out of the leaf, transparent to let light through
• Epidermis cell: Covers the outside of the organ, transparent to let light through
• Palisade cells: Contain chloroplasts
• Spongy Mesophyll: Air spaces so carbon dioxide can diffuse through
• Stomata: Regulates the amount of water lost from the leaf
• Vascular bundle: Contains:
  • Xylem: Carries water and minerals from root to leaf
  • Phloem: Carries water and food in both directions

Yeast cells contain:

• Cell Membrane & Vacuole
• Nucleus & Cytoplasm
• Food Storage granule

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Digestive System:

• Pancreas and salivary glands: Produce digestive juices
• Stomach and Small Intestine: Digestion takes place
• Liver: Produces bile
• Small Intestine: Soluble food is absorbed
• Large intestine: Water is absorbed from undigested food, producing faeces