Cells & Tissues in the Human Body PDF

# CELLS - Biologicial molecules are formed of: - Carbohydrates: sugars → main energy source of cellular metabolism - Lipids: fats → main component of cell membranes - Protein: meats, eggs etc. → most of the cell is made of proteins - Nucleic acids: cell’s genetic material (DNA) ##...

# CELLS - Biologicial molecules are formed of: - Carbohydrates: sugars → main energy source of cellular metabolism - Lipids: fats → main component of cell membranes - Protein: meats, eggs etc. → most of the cell is made of proteins - Nucleic acids: cell’s genetic material (DNA) ## CELL STRUCTURE - Eukaryotic animal cells - **Cell Membrane** - protection - bilayer - semi-permeable (O2, CO2, glucose, H2O) - protein - **Cytoplasm** - holds water - internal environment - holds organelles - **Nucleus** - brain of the cell - membrane - contains DNA - **Golgi Apparatus** - stacked membrane - makes vesicles (“containers”) - **Cilia** - allow movement - tube-like structure - like limbs - outside of cell - **Lysosomes** - break down substances - transport substances - **Flagella** - same as cilia but longer and less abundant - **Vacuoles** - water storage - **Mitochondria** - double membrane - makes energy - **Endoplasmic Reticulum (ER)** - making lipids - rough ER (ribosomes) - smooth ER (no ribosomes) - The difference between organelles and macromolecular complexes is that organelles have a membrane. - **MMR (macromolecular complexes):** - **Centrioles:** - responsible for moment inside cell - role in cell division - **Cytoskeleton:** - support in cytoplasm - holds the structures in place - tube-like - **Ribosomes:** - role in cell division - movement in cell membrane - **Proteasomes:** - clean rubbish like dirty protein - do this by degrading - **Prokaryotic cells:** are a unicellular organism, simpler and smaller than eukaryotic cells. ## GENETIC MATERIAL - Every living thing or organism has genetic material. - The genetic material is unique to each organism (except identical twins). - Every cell in your body has the same genetic material because it was once a singular cell, half from the female sex cell and half from the male sex cell. - **Genetic material = DNA = deoxyribonucleic acid** - Provides the instructions for structure and function of the cell. - **Nucleic acid bases:** - A, C, G, T - A-T - C-G - **Gene characteristics:** # TISSUES IN THE HUMAN BODY ## Epithelial - tightly bound cells - little intercellular material (ECM) - cover organs and body surfaces ### Covering and lining - protects and covers organs - forms cell layers ### Secretory Epithelia - made of cells that produce and secrete substances onto the epithelial surface ## Connective - Cells with abundant matrix, or intercellular material ### Connective tissue proper - fill spaces between body’s organs ### Adipose tissue - made of cells that store lipids as energy reserves ## Cartilage - flexible, strong matrix - framework for structures - covers joints ## Bone - most rigid tissue - mineral salts ## Blood - cells suspended in a fluid matrix called blood plasma # Muscle tissues - main component of muscles, made up of bundles of elongated cells, called muscle fibers ## Smooth - Smooth muscle tissue is formed by cells that have a single nucleus. - It is found on the walls of organs such as the stomach and bladder. ## Skeletal - Skeletal muscle tissue is formed of cells with several nuclei. It makes up the muscles that move the skeleton. ## Cardiac - Cardiac muscle tissue is the tissue found on the walls of the heart. - Uninuclear # Nervous tissues - nervous tissue is a highly specialized tissue made up of cells neurons with the ability to react to stimuli and transmit responses to effector organs. # CELLULAR ORGANISATION ## Sexual Reproduction - Female - egg cell - Male - sperm cell - **50% genetic material + 50% genetic material = 100% genetic material (zygote = first cell of life)** - **Sex cells (gametes) contain only 1/2 of the genetic material** - 0 -> 00 -> 000 -> 0000 -> 00000 -> 000000 -> 32… - **Every cell in the body has the same genetic material.** - tube - ovary - zygote - uterus - … - skin - muscle cells - sex cells - blood cells - neurons - **Cell differentiation**