Biology Flashcards
What is a cell surface membrane?
A thin skin around the cell which controls what goes in and out and holds the cell together
What are mitochondria?
Tiny structures within a cell where most of the reactions for aerobic respiration take place. Respiration releases energy for the cell.
What is the nucleus?
Structure that contains the DNA of a cell, controls what the cell does.
What is the cytoplasm?
Jelly-like substance where most chemical reactions happen.
What is the cell wall? (plant)
Rigid outer coating made of cellulose, gives support to the cell.
What is a permanent fluid-filled vacuole? (plant)
Weak solution of sugar and salts–> cell sap
What are chloroplasts?
Structures which contain chlorophyll, a green dye used for photosynthesis- makes food for the plant.
What is an organ system?
system consisting of several organs working together to perform 1+ functions
What are the seven life processes?
- Reproduction
-Sensitivity (Response, reaction)
-Growth - Excretion
-Nutrition
-Respiration
-Movement
What are carbohydrates used for?
- fuel for the body- provides it with glucose molecules
—> release all the energy it needs through respiration
What are proteins used for?
Raw materials for growth and repair of damaged tissue
What are lipids used for?
-Insulation (warmth)
- Energy store if body runs out of carbs.
What are minerals used for?
-Iron=blood
-Calcium=bones
- Sodium= nerve cells
What are Vitamins (small amounts) used for?
Keep vital processes happening.
What is fibre used for?
Keep food moving through digestive system, prevent constipation
What is water used for?
-Body is 60 percent
- All chemical reactions, e.g digestion, take place in water
Vit. C deficiency consequences?
Scurvy- problems with skin, joints and gums
Calcium deficiency consequences?
Osteoporosis- bones less dense, more likely to fracture
- Rickets(kids)- Weak and soft bones.
What happens if you eat too little?
-If needed energy is not supplied, the body will use up lipid stores.
- Lose weight, tired and weak
- Eventual starvation
What happens if you eat too much?
- Extra energy stored as fat, put on weight
- Risk to health –> obese
- Health problems such as high blood pressure, heart disease.
Too much saturated fat?
Increased blood cholesterol level –> high risk of heart disease
Food test method?
- Break up sample with pestle and mortar
- Beaker, distilled water
- Stir to dissolve some food
- Get rid of solid bits using filtration
What solution tests for sugar? What happens when contained?
Benedict’s solution, heated, goes from blue to green to orange to red if present. More change= more sugar.
What drug does tobacco contain, and what are its adverse side effects?
Nicotine(makes it addictive and pleasureable), the smoke in tobacco contains chemicals like tar which can damage the lungs.
