Day 8 GHSGT Tutoring Biochemistry and Cell Processes

The cells need nutrients to provide nourishment and energy. The main nutrients of the cell are proteins, carbohydrates, lipids (fats), and nucleic acid.

Carbohydrates (C,H, and O molecules in a ratio of 1:2:1) Carbohydrates are an important energy source for cells.

TYPES OF CARBOHYDRATES Monosaccharide – simple sugars made of one sugar molecule. (ex. Glucose)

TYPES OF CARBOHYDRATES Disaccharides – (ex. Sucrose) 2 monosaccharides linked together

Polysaccharides – ex. Starch, Cellulose) More than two sugars linked together. TYPES OF CARBOHYDRATES

Simple Carbs ~ mono and disaccahrides Complex carbs ~ starches, polysaccharides

LIPIDS Made up of two parts: – A polar head made of C,H, and OH links – A non-polar tail made of a hydrocarbon chain. This arrangement allows the lipids to form bilayers creating waterproof barriers in a cell’s membrane.

LIPIDS insoluble in water Fatty acids, waxes, fats, steroids and oils are formed by lipids (all are insoluble in water)

Proteins Molecules made up of one or more chains of amino acids. They are used for many functions…

Proteins are used for… Structure – they make collagen in skin and keratin in hair/nails/horn

Proteins are used for… Movement ~ actin and myosin in muscle stimulate the muscle to move

Proteins are used for… Defense ~ antibodies in bloodstream

Proteins are used for… Storage ~ corn seeds are predominately made of protein

Proteins are used for… Signals ~ growth hormones in your blood stream

Proteins are used for… Nucleic Acids (used in DNA or RNA) – long chains of subunits called nucleotides. All nucleotides have the following… 1. five carbon sugar (ribose or deoxyribose) 2. phosphate group 3. nitrogen-containing base (A,T,C or G)

Cells of the body system work closely together to maintain the proper balance of oxygen, salts, water and other substances the organism needs to carry on life processes which contribute to the life of the whole organism

How does a cell maintain homeostasis? The ability of a unicellular or multicellular organism to maintain a constant internal balance regardless of changes in the external environment is known as homeostasis. Cells move fluids and nutrients in and out through the cell membrane by either passive or active transport in order to maintain homeostasis.

Passive Transport – spontaneous and does not require energy. The molecules move from areas of high concentration to areas of low concentration. There are 2 types – diffusion and osmosis

Diffusion – substances move from areas of higher concentration to areas of lower concentration

Osmosis – movement of water through a semi- permeable membrane from an area of high water concentration to an area of low water concentration. CLICK HERE FOR ANIMATION OF DIFFUSION AND OSMOSIS

CLICK HERE TO DEMONSTRATE HYPERTONIC/HYPOTONIC Effects l Hypotonic Solution – more water goes in than out, the cell swells Hypertonic Solution – more water goes out than in, the cell shrinks Isotonic Solution – equal amounts of water go in and out, the cell remains the same

Active Transport – not spontaneous. A cell uses stored energy to move substances across the cell membrane in the opposite direction of concentration. click here to see active transport Exocytosis – form of active transport in which a cell discharges materials out of the cell Endocytosis – form of active transport in which a cell imports substances into the cell

Photosynthesis – the process in which a plant makes food from water and carbon dioxide using energy from the sun. The green pigments in plants are able to use sunlight and carbon dioxide from the air, along with water taken in through the roots of the plant, and change them into food. This food is stored in the plant as glucose, which is a form of sugar. 6CO H 2 O  C 6 H 12 O O 2

Respiration – a series of chemical changes within a cell in which sugar is broken down, oxygen is used, energy is released, and water and carbon dioxide are produced. Respiration takes place in the mitochondria of the cell. Animals take in food and break it down through digestion. It is then carried by the blood cells where cellular respiration takes place. C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP)