Cells in Tissues, Organs, and Systems (Page 7-16) Cells develop particular characteristics to adopt to their specific environment and function: − − − Blood cells transport gases. Nerve Cells conduct impulses. Muscle cells contract and relax. Adaptations of Plant and Animal Cells Specialized plant and animal cells have specific adaptations for their role in environment. Organization of cells All living organisms have levels of organization from atoms to molecules to organelles in cells. Cells are also specialized and organized into groups that perform specific functions. - A group of differentiated cells that perform a common function is known as a tissue. - Ultrathin cells line the lungs to allow for easy diffusion of gases - A group of different tissues, each with their own function, that performs a common function, is known as a organ - Spiral thickening strengthens the walls of an empty plant cell (xylem vessel) for the upward transport of water - A group of different organs, each with their own function, that performs a specific function, is known as a system. - Finger like extension of a root cell to increase surface area for absorption of water from the soil. - A group of different systems, each with their own function, is known as an organism. - Bean shaped cells in the leaf surface have think inner walls to control opening/ closing of a pore for gaseous exchange. -Digestive system - Many, long outgrowths of a nerve cell for optimal transmission of nerve impulses. - Tiny hairs on cells in the nose to trap foreign bodies and protect the lungs. Unicellular vs Multicellular Main body systems: Breaks down food for absorption. - Circulatory system Transports gases, nutrients, and waste - Respiratory System Supplies π2 and removes πΆπ2 - Skeletal System Unicellular Organisms Multicellular Organisms - Consist of a single cell - Simple level of organization - A single cell performs all the processes for life - Microscopic organisms smaller in size - Only visible under a microscope - e.g., bacteria and yeast fungus, Bacterium, Amoeba, Euglena - Consist of large numbers of cells - Complex level of organization - Cells are organized into groups that are specialized to perform a particular process - Macroscopic organisms larger in size - Visible to the naked eye - e.g., Humans, animals, plants, elephant, fern, crab - Muscular system (musculoskeletal) support, protection, and - Excretory System Removes waste and regulates water and salts. -Nervous System Receives and respond to stimuli. - Reproductive system Enables intercourse, provides sex cells and support for offspring. Other systems: Endocrine system: Hormones Integumentary system: Skin Immune System: Resistance to disease Overview: Main Processes: Main Components: Structures and Functions of the Digestive 1. Ingestion The main structures involved in the digestive system. Organs - The intake of food into the mouth Mouth and Mouth Cavity Mouth 2. Digestion - The breakdown of large insoluble molecules into smaller soluble molecules that can be absorbed into the bloodstream - Digestion begins in the mouth with the teeth, tongue and saliva breaking down food - Digestion also occurs in the stomach and intestines with the muscle action and enzymes -chewing: Teeth and tongue - Lubrication: Saliva -Digestion: Teeth and saliva - Swallowing: Tongue Oesophagus Salivary Glands - Secretes saliva: For lubrication and digestion 4. Egestion: - Undigested food is removed from the body un the form of faeces (stool) via the anus. Health Issue Causes Ulcers Oesophagus - Tube between moth and stomach - Muscular action: Squeezes food Stomach Liver Mouth and mouth cavity, oesophagus, stomach, small intestine, large intestine, rectum, anus Accessory organs: - Releases bile to digest fats - Stores excess glucose - Breaks down alcohol and other toxins -Tongue: Mixes food, taste -Salivary glands: secretion of saliva - Pancreas: Secretion of pancreatic juice and insulin Stomach Small Intestine - Digestion: Churning action mixes food. - Digestion: Digestive juices break down food. Liver: Secretion of bile, storage of glucose, detoxification of blood Gall bladder: Storage of bile Types of digestion: Mechanical Intestines Small intestine: Digestion by enzymes and absorption Large intestine: Absorption of water and formation and decomposition of faeces. Rectum digestion - The physical breaking of food into smaller particles Anus Chemical digestion - Mixing of food with digestive enzymes to break down food on the molecular level. Anus - Ring muscle at the end of intestine - Egestion: Release of faeces. Anorexia Nervosa The role of the alimentary canal is to digest food into smaller soluble nutrients that can be absorbed by the blood stream and taken to cells for energy, growth and repair of damaged tissues and several other body processes. Alimentary canal: 3. Absorption: - Soluble endproducts of digestion that are transferred from the gut, through the walls, into the surrounding blood vessels for transport to the cells in the rest of the body. The alimentary canal is a longtwisted tube that runs through the body from the mouth opening at the top to the anus at the end. Diarrhoea Liver Cirrhosis Tongue: Mixing of food, taste Mouth: Ingestion, lubrication, swallowing, mastication, digestion Salivary glands: Secretion of saliva Oesophagus: Peristalsis, digestion Note: Adaptations always refer to structure and function. Stomach: Churning, digestion, secretion of gastric juice Symptoms Pancreas: Secretion of pancreatic juice and insulin Rectum: Storage of faeces Anus: Egestion Liver: Secretion, storage, detoxification Gall bladder: Storage of bile Large intestine: Absorption, peristalsis Small intestine: Peristalsis, secretion of intestinal juice, digestion, absorption Enzymes Enzymes Special proteins that speed up chemical reactions and aid the Special proteins breakdown/building up of molecules. that speed up chemical reactions Anus Enzymes Ring-shaped muscle at the end of the gut that controls the Special proteins removal of faeces from the body. speed up that chemical reactions Gut Enzymes Alimentary canal, particularly stomach and intestines Special proteins Decomposition Enzymes Breakdown or decay of matter Special proteins 5 main processes in the Enzymes alimentary canal - Ingestion Special proteins - Digestion that speed up - Absorption - Assimilation chemical - Egestion reactions and aid the Food Bolus Enzymes A round ball of chewed food that is mixed with saliva in the Special proteins mouth cavity and pushed in the direction of the that speed up oesophagus during swallowing. chemical reactions and aid Note: Gastric juice consists of hydrochloric acid produced by the walls of the stomach and enzymes, which are special proteins that speed up chemical reactions. Note: A highly folded surface increases the total surface area which increases the absorption rate. Note: The accessory organs do not form part of the alimentary canal, but they assist the alimentary canal in its functioning. Note Blurt Cell structure • • β β β β the cell is the basic structural and functional unit of all living organisms. Cells can be seen under a microscope (they are microscopic) plant and animal cells have a cell membrane, cytoplasm, nucleus, and organelles such as mitochondria, vacuoles, and chloroplasts (just plant cells) the cell membrane encloses the contents of the cell. It allows specific substances to pass into and out of the cell. the cytoplasm is the jelly-like medium in which many chemical reactions take place. the nucleus contains DNA. the nucleus is enclosed by a nuclear membrane (in plants and animals) DNA contains inherited characteristics, such as whether eyes are blue or brown. DNA is unique to each person; this variation accounts for differences within species. Mitochondria are responsible for respiration to release energy from food. Cell structure • • • • • cells come in many different shapes and sizes. cells are adapted to perform specific functions, such as muscle cells which are specialised to contract and enable movement. microscopic organisms such as bacteria, consist of a single cell. Macroscopic organisms such as humans, consist of large numbers of cells. a group of cells performing a specific function form a tissue, a group of tissues make up an organ, and organs working together in groups form systems, systems make up an organism. stem cells are cells that can divide and develop into many different cell types [No detail required] CHARACTERISTICS OF LIFE CELL The things that distinguish living (biotic) things from non-living (abiotic) things: •M -Movement •R -Respiration •S –Sensitivity (response to changes in environment) •G -Growth •R –Reproduction •E -Excretion •N -Nutrition Smallest unit of life that can perform all life processes. CELL THEORY CELLS: THE BASIC UNITS OF LIFE •Simple organisms such as bacteria, are single cell (unicellular). •Plants and animals are made up of many cells (multicellular). •Each kind of cell has a particular function. Atom Molecule or compound . All cells develop from already existing cells. CELLS: SIZE & SHAPE •Size and Shape depend upon its function. •Red blood cells are small and disc shaped to fit through the smallest blood vessel . •Muscle cells are long and thin. When they contract, they produce movement. •Nerve cells which carry signals to the brain are very long. TISSUES, ORGANS, & SYSTEMS Functions Of Cells: •Cells that work together to perform a specific function form a tissue. •Just as cells that work together form a tissue, tissues that work together form an organ. •Organs that work together to perform a function form a system. Example: circulatory system. •Plant cells also form tissues, such as the bark of a tree. And plant cells work together, forming organs, such as roots and leaves. - Cells work together to perform basic life processes that keep organisms alive - Getting rid of body wastes - Making new cells for growth and repair - Releasing energy from food Cell Organelle Tissue Organ Organism Organ System Organelles CELL MEMBRANE-the thin layer of protein and fat that surrounds the cell. The cell membrane is semipermeable\selectively permeable, allowing some substances to pass into the cell and blocking others. •CELL WALL-a thick, rigid membrane that surrounds a plant cell. This layer of cellulose fibre gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant. Permeable to most substances •LYSOSOME- (also called cell vesicles) round organelles surrounded by a membrane; they contain digestive enzymes. This is where the digestion of cell nutrients takes place. Found in animal cells only. NUCLEUS–round body. The nucleus controls many of the functions of the cell (by controlling protein synthesis) and contains DNA (in chromosomes). The nucleus is surrounded by the nuclear membrane. •NUCLEAR MEMBRANE-the membrane that surrounds the nucleus. •NUCLEOLUS-an organelle within the nucleus -it is where ribosomal RNA is produced. Some cells have more than one nucleolus. DNA –DEOXYRIBONUCLEIC ACID: Determines an organisms inherited characteristics (i.e., eye\hair colour). Unique to each person. Children inherit a mixture of mom and dad’s DNA. Accounts for the variation within species. ANIMAL CELL VACUOLE-fluid-filled, membrane-surrounded cavities inside a cell. The vacuole fills with food being digested and waste material that is on its way out of the cell. PLANT CELL VACUOLE-a large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single vacuole that takes up much of the cell. It helps maintain the shape of the cell. •Determines an organisms inherited characteristics (i.e., eye\hair colour). Unique to each person Children inherit a mixture of mom and dad’s DNA. Accounts for the variation within species •Determines an organisms inherited characteristics(i.e. eye\hair colour)•Uniqueto each person•Children inherit amixtureof mom and dad’s DNA.•Accounts for the variationwithin species •MITOCHONDRION–round to rod-shaped organelles with a double membrane. The inner membrane is infolded many times (large surface area) •The mitochondrion converts the energy stored in glucose (sugars) into energy that can be used by the cell –cellular respiration. •RIBOSOME-small organelles composed of RNA and proteins that are sites of protein synthesis. Protein Synthesis –building proteins by linking amino acids together to form long chains. •Synthesis = “to make” •CYTOPLASM-the jellylike substance in which the organelles are located. Provides liquid medium for all the chemical reactions that take place in the cell. •PLASTIDS: Chloroplasts, chromoplasts, leucoplast. ONLY in plant cells. Chloroplasts = photosynthesis (contain chlorophyll). Chromoplasts= coloured pigments, colour of fruits and flowers, chloroplasts change to chromoplasts when fruit ripen. Leucoplasts = store food, amyloplasts when store starch, may change into chloroplasts if exposed to sunlight. •CHLOROPLAST–oval shaped organelle containing chlorophyll. •Photosynthesis (in which energy from sunlight is converted into chemical energy -food) takes place in the chloroplasts. Chlorophyll is the pigment that makes plants green. Differences between plant and animal cells plant cells differ from animal cells. Plant and animal cells are enclosed by a cell membrane, and plant cells also have rigid cellulose cell walls to provide support for the plan. Plant cells also contain organelles such as large vacuoles and chloroplasts. Chloroplasts contain chlorophyll to absorb light energy for photosynthesis (refer to Grade 8 Life & Living). Vacuoles in plant cells have several functions including support and storage (Vacuoles in animal cells are small and temporary or absent) Overview: Main processes: Blood Health issues Health issue Causes Symptoms High blood Heart pressure/hypert attacks ension Strokes Overview: Main Processes: Diffusion: The movement of particles from an area of high concentration to an area of low concentration. Main Components: Allergens Organelles Organelle Description Function Cell Wall - Tough, fibrous, non-living structure that surrounds protoplasm - It is present in only cells - Composed of cellulose; outer layer of cellulose or chitin - Protects and supports the cell Provides shape + strength + support Cell Membrane (Plasma membrane) - Forms a thin outer boundary for contents of the cell -Controls the movement of. substances in and out of the cell (it is selectively permeable) - Surrounded by a rigid cell wall for additional support - Substances move by osmosis …across the cell membrane. -Jelly like fluid matrix inside the cell …membrane. - Medium in which chemical …reactions occur - Food is stored in cytoplasm - Maintains shape of cell - Dark, round/oval structure in the cytoplasm - It is enclosed by a nuclear membrane. - Contains fluid called nucleoplasm. - Controls all the activities of a cell. - Controls the entry/exit of substances in and out. - Useful substances are allowed and unwanted …substances are blocked - Regulates the movement of substances - Receptor molecules respond to chemicals - Animal and plant cells - Cigar/cylinder shaped, double membrane - Folded in membrane - Releases energy from food - Uses oxygen releases CO2 - Fluid filled sac in the cytoplasm; Filled with liquid called cell sap - Enclosed by the tonoplast – a selectively permeable membrane - Plant cells have larger vacuoles that provide support, storage, and shape for the plant cell - Animal cells have smaller vacuoles called contractile vacuoles that regulate the water balance - Oval shaped, green organelle called a plastid - Occurs in photosynthesising parts of a plant - Surrounded by a double membrane filled with liquid - Cite of aerobic respiration - Transforms energy in fuel into accessible forms of energy Lysosome Small, round structures, containing enzymes Golgi Complex Small bags with tubes connecting them - Breaks down large molecules and old cell parts into their components that can be recycled to build new cell parts - Receives products from the ER and adds final modifications. It also sorts these products and sends them to their final destinations. Nuclear membrane Nucleolus Ribosome Thin covering over the nucleus Site of genes for rRNA synthesis Small specks made of RNA. Found in cytoplasm or on the endoplasmic reticulum Rough endoplasmic reticulum Network of internal membranes Smooth endoplasmic reticulum Network of internal membranes Centriole Small cylindrical Cytoplasm Nucleus Mitochondrion (single) Mitochondria (plural) Vacuole Chloroplast - Maintains shape of cell - Substances are dissolved or suspended in cytoplasm - Carries inherited characteristics on DNA (deoxyribonucleic acid) which is coiled to form chromatin threads in the …nucleoplasm: - DNA contains the coding for the structure and functioning of a cell. - DNA coding is arranged in units called genes and occurs in the nucleus of every cell in the body of an organism. - DNA causes variation within a species: ~DNA in people is unique. Basically, a membrane enclosed sac that can be filled with anything the cell needs to keep separate. Stores food, water, etc. In plants the vacuole also helps the cell maintain its rigidity. - Converts light energy from the sun, water, and carbon dioxide to carbohydrates for food. - - Assembles ribosomes Smallest organelle found in ALL cells. Builds proteins by putting together long chains of Amino Acids according to the mRNA message (a copy of a piece of DNA) Thousands in each cell. Large, folded membrane system studded with Ribosomes. Ribosomes build proteins and the ER helps fold or modify them. Products are shipped to the Golgi Large, folded membrane system studded with ribosomes. Ribosomes build proteins and the ER helps fold or modify them. Products are shipped to the Golgi The centrosome is responsible for organizing the microtubules (made of proteins) in the process of mitosis, therefore, it is also known as microtubule organizing centre of cell. It also plays a major role in cell division and helps in providing the shape and structure to the cell. Glossary GLOSSARY Cells: Organelles the structure of cells → → → → → → → → → → → → → → → → → → → → Vacuole Nucleolus Nucleus Cytoplasm Mitochondrion Cell membrane Adaptations of animal cells Organelles Cell Wall Cell membrane Nucleus DNA Cytoplasm o o o Mitochondrion o o o Organelles Continued Vacuole Diagrams Chloroplast Difference between plant and animal cells (Chapter 2)
