Mid-Year review

Sec 3

2012-2013

Science Review: Part 1

The Living World

Cells

• The smallest “unit” of life is the cell

Name of Part Function

Nucleus Contains the DNA

Controls the cell’s activities

Cytoplasm Liquid in the cell

Cellular membrane Controls what enters and exits the cell

Cells

• Cells have many different functions– They can be nerve cells, sex cells, blood

cells, ect…

– Cells → Tissues → Organs → Systems

Cells

• How a cell divides (multiplies itself to ensure growth and repair) depends on the function of the cell

– All cells (except sex cells) muliply via mitosis

– Gametes (sex cells) are produced via meiosis

Characteristics of Mitosis:

• 1 parent cell (23 pairs of chromosomes)

• Duplicates its DNA

• Splits into 2 identical cells (23 pairs of chromosomes)

Characteristics of Meiosis:

• 1 parent cell (23 pairs of chromosomes)

• Duplicates its DNA• Splits into 2 identical cells

(23 pairs of chromosomes)

• Each daughter cell splits again forming a total of four genetically unique cells with only 23 chromosomes

To summarize…

MitosisMitosis MeiosisMeiosisOccurs for all cells except gametes (sex cells)

Occurs only in gametes

Produces 2 cells Produces 4 cells

Produced cells are identical Produced cells are genetically different

End cells have 23 pairs of chromosomes

End cells have 23 chromosomes

• Genetically Modified Organism (GMO)– Occurs when we tinker with the DNA of a cell.– By changing the chromosomes in the nucleus

we can give different characteristics to the organism

• Resist frost• Spider goat

Cells

• In order to perform their function, cells require energy, which they get by performing cellular respirationcellular respiration

Glucose + Oxygen → Carbon dioxide + water + ENERGY

Digestive System

• Role of the digestive system:– Decomposes food into smaller nutrients– Absorbs nutrients and water– Eliminates waste

Topic 1: The Digestive System

• Nutrients– Function– Energy value– Broken down elements

• Anatomy

• Physiology

Nutrient Chart

NutrientsNutrients FunctionFunction Energy Energy valuevalue

SourceSource Broken Broken down intodown into

Carbs 1st energy supply

17 kJ/g Breads, sugar, pasta

Glucose

Lipids (fats) 2nd energy supply

37 kJ/g Oils, butter, meats

Glycerol

Fatty acids

Proteins Emergency energy supply

Helps build and repair tissues

17kJ/g Meats, nuts Amino Acids

Nutrient Chart

NutrientsNutrients FunctionFunction Energy Energy valuevalue

SourceSource Broken Broken down intodown into

Water Regulates Metabolism

None Fruits, vegetables, water

Absorbed directly

Vitamins Regulates Metabolism

None Fruits, vegetables

Absorbed directly

Minerals Regulates Metabolism

None Fruits, vegetables

Absorbed directly

Fiber Regulates Metabolism

None Fruits, vegetables

Not absorbed

• What are the energy giving nutrients?

• If you are injured what nutrient should you eat?

• What is a source of carbohydrates?

• Calculate the energy value of a cookie with 6 g of carbs and 12 g of fats?

• What do proteins break down into?

• Name the nutrients that help regulate metabolism.

C is for Cookie?

Or Calculation?

C is for Cookie…

Cookies:

Protein 2.1 g

Fat 7.7 g

Carbs 24 g

2.1 g x 17 = 35.7 kJ

7.7g x 37 = 284.9 kJ

24 g x 17 = 408 kJ

Total: = 728.6 kJ

Function:Function:These cookies are therefore an These cookies are therefore an energy energy producerproducer but are also very high in fat but are also very high in fat

C could be for last minute CRAM

Topic 1: The Digestive System

• Nutrients

• Anatomy– The digestive tract– Sites of Absorption

• Physiology

Physiology

Mmmm!!

Burger

Anatomy

• The digestive system:– The digestive tract

• Path the food takes

– The digestive glands• Where chemicals that help in the breakdown of

food comes from

Glands = organs that secrete an enzyme (chemical)

Anatomy

• The digestive tract

–The Mouth– The Pharynx– The Esophagus– The Stomach– Small Intestine– Large Intestine

Anatomy

• The digestive tract– The Mouth

–The Pharynx– The Esophagus– The Stomach– Small Intestine– Large Intestine

Shared by the respiratory system and the digestive system

Anatomy

• The digestive tract– The Mouth– The Pharynx

–The Esophagus– The Stomach– Small Intestine– Large Intestine

PERISTALSIS: muscle contractions that push food through the digestive tract

Anatomy

• The digestive tract– The Mouth– The Pharynx– The Esophagus

–The Stomach– Small Intestine– Large Intestine

*Churning: action of the stomach to mix the food with the gastric juices

Anatomy

• The digestive tract– The Mouth– The Pharynx– The Esophagus– The Stomach

–Small Intestine– Large Intestine

*Peristalsis

*Site where nutrients are absorbed

Anatomy

• The digestive tract– The Mouth– The Pharynx– The Esophagus– The Stomach– Small Intestine

–Large Intestine

Topic 1: The Digestive System

• Nutrients

• Anatomy

• Physiology– How does the system work

Physiology

Mmmm!!

Burger

What happens?

• Mouth:– Mechanical breakdown: chewing– Chemical breakdown of carbscarbs because of the

saliva from the salivary glands

What happens?

• Pharynx:– Not Much

What happens?

• Esophagus:– Mechanical breakdown: Peristalsis

What happens?

• Stomach:– Mechanical breakdown: churning– Chemical breakdown of proteinsproteins because of

the pepsin from the gastric glands– Chemical breakdown with the stomach acid

What happens?

• Small Intestine:– Mechanical breakdown: peristalsis– Mechanical breakdown of lipids because of

the bile from the liver

– Chemical breakdown of all foodall food because of the Intestinal juices

• Major part of digestion occurs

What happens?

• Large Intestine:– Mechanical breakdown: peristalsis

• Where do carbs get chemically broken down?

• Where do proteins get chemically broken down?

• Where do the lipids get chemically broken down?

• Into which part of the digestive tract does the liver and pancreas secrete their enzymes?

Physiology

• During the digestion process your food undergoes mechanical and chemical transformations

– Mechanical Transformation: same thing only smaller or mixed

– Chemical Transformation:break down of complex molecules into less complex molecules

Examples of Mechanical Transformations

• The Mouth – Chewing

• The Stomach and small intestine- Churning– Mixing food with the secretions of the

digestive glandsPeristalsis is also a mechanical transformation

Physiology

Mmmm!!

Burger

Absorption of nutrients

• The process that moves nutrients (chemically broken down food) through the lining of the digestive tract and into the blood stream.

• Mostly, food is absorbed in the small intestine via Villi.

What is a Villi?

• Folds in the intestine

• Increases surface area

• The small intestine absorbs:– Lipids (fatty acids and glycerol)– Carbohydrates (glucose)– Proteins (amino acids)

• The large intestine absorbs:– Water– Vitamins– Minerals

Physiology

Mmmm!!

Burger

The Material World

In less than 30 minutes

• Everything around us is made of atoms and molecules

• To simplify how we see things, we will represent these tiny atoms and molecules using the particle model

• An element is more of the same particle

• A compound is when there are two or more types of elements/ atoms in a molecule (the particles must be touching)

Elements turn into compound through chemical reactions that result in a gain of mass or a change of color

Moral of the story

• A pure substance is when a substance has the exact same chemical composition

• A mixture is well, a mixture

Moral of the story

• A pure substance is when a substance has the exact same chemical composition

• A mixture is well a combination of more than 1 type of molecule or element

• Would salt water be considered a pure substance?

• What are the 2 signs for changing an element into a compound?

• Is O2 an element or a compound?

Physical Change vs. Chemical Change

• Physical Change– The chemical nature of the substance stays

the same• Dillution• Dissolution• Phase Change

• Chemical Change– The chemical nature of the substance is

altered

Properties

Density

• Density (ρ) is mass on Volume– ρ = m/V

• ρ is different from p

• m = How much matter it has• V = how much space does it take up

The General rules…

Regular solids

Irregular solids

Liquids Unit

mass Weigh Weigh Liquid mass g

Volume Length x width x height

Water Displacement

Measure it in the graduated cylinder

ml or cm3

Density m Weigh Liquid mass g/ml or g/cm3

v Water Displ. Measure in g.c.

Identifying solids

• Best to verify density

• Color

• Electrical conductivity

• Boiling point

• Melting point

• Magnetism

Identifying liquids

• Cobalt Chloride – positive test = water

• Electrical conductivity– positive test = either salt water, acid or base

• Blue litmus paper– if it turns red = acid

• Red litmus paper– if it turns blue = base

Identifying Gases

• Flaming Splint– Positive test = hydrogen

• Glowing splint– Positive test = Oxygen

• Limewater– Positive test = Carbon Dioxide

Graphical Language

1. There exists many ways to represent an object

a) Sketch vs. diagram vs. Technical Drawing

The difference

• A Sketch– Drawing made without instruments or

measurements

• A Technical Drawing– Drawing made with instruments, made to

scale, and serves as a reference, therefore it follows conventions

• Technical drawings include– Diagram of principles

• Shows how the object works

– Construction diagram• How to build the object

Sketch it

2. In order to properly communicate through technical drawings, we need a common set of conventions (rules)

to follow.

a) Lines

Line type Function

Visible Line Shows the visible details of an object

Hidden Line Shows the hidden details of an object

Center Line Shows the center of a circle

Dimension Line

Indicates a dimension (mm)

Extension Line

Indicates from where a measurement is taken place

a) Lines (cont.)

Line type Function

Cutting Plane Line

Indicates the position of an imaginary cut

Hatched Line

Shows the surface that has been cut

Leader Line Points to a specific part of the drawing

b) Scale

• The scale:– A relationship between an object’s dimensions

in a drawing and the object’s actual dimension

– Drawing size : Real Life size• 1:1 = actual size representation• 2:1 ; 3:1; 25:1 = scale of enlargement• 1:2 ; 1:4; 1:25 = scale of reduction

c) Perspective

• Definition:– A form of representation that gives the

impression of depth

– Yet can distort the image when drawing it in 2D

D) Projections

• i) Multiview– Shows a detailed view (using various lines) of

3 sides of an object without distortion

Top

Front Side

D) Projections

• ii) Isometric– 3D representation of an object that shows all

three sides at once

c) Projections

• iii) Oblique– Representation of an object using

perspective. – The drawing is highly distorted (depth

reduced by half)

C) Projections

• Axonometric– Exploded view of an object showing how to

assemble it

– Will always be accompanied with a list of materials (nomenclature)

Mechanical Engineering

Assembling parts

1. There are certain components in technical objects that serve

specific purposes to ensure the proper functioning of the system

a) Typical functions to ensure proper functioning

• Sealing– To seal

• Lubricating– To reduce friction

• Guiding– Allows specific motions

• Links– To connect components together

2. Guides allow a component to move in a specific manner

2. Guides

• Freedom of motion– Rotation and/or translation around the x, y, or z

axis

• Types of guides– Rotational guide: ensures rotation– Translation guide: ensures translation– Helical guide: ensures rotation

and translation around

the same axis

3. Links connects different parts of a technical object together

a) Each link will have 4 characteristics

Direct Indirect

Flexible Rigid

Removable Non-Removable

Complete Partial

b) Characteristic definitions

• Direct: – The two pieces fit

without requiring another component

– E.g. puzzle pieces– E.g. Pen cap and the

pen

• Indirect:– The two pieces need

an extra component to hold them together

– E.g. A poster and the wall

– E.g. 2 pieces of paper

b) Characteristic definitions

• Flexible: – The linking component

or materials are flexible

– E.g. Sticky tack– E.g. velcro

• Rigid:– The linking component

or materials are non flexible

– E.g. A nail– E.g. a dowel and a

base

b) Characteristic definitions

• Removable: – Can be removed

without damaging the material or linking component

– E.g. Screw– E.g. Sticky Tack

• Non-Removable:– Cannot be removed

without damaging the material or linking component

– E.g. A nail– E.g. Glue

b) Characteristic definitions

• Complete: – Does not allow any

movement between the pieces

• Partial:– Allows some

movement between the pieces

Technological Drawings

1. Sketch vs. Diagram vs. Drawing

Sketch vs. diagram vs. drawing

• Sketch : quick free hand drawing

• Diagram: (how the object is made)

• Drawing: (how the object looks)

2. Basic lines

Basic Lines

• Visible Contour Line

• Hidden Contour Line

• Center Line

• Extension Line

• Dimension Line

What is the difference?

What is the difference?

3. Types of Projections

Projections

• Oblique– 1 face is parallel to the paper– Depth is altered

Projections

• Orthogonal– Isometric

• All three sides are shown

Projections

• Orthogonal– Multiview

• Shows all three sides with details

Projections

• Axonometric– Shows in details all parts of an object– Also called the exploded view– Comes with a list of parts (nomenclature)

4. Scales

What is it?

What is it?

Purpose of scales

• Reduction Scale– 1:2– 1 mm in the drawing represents 2 mm in real life

• Enlargement Scale– 2:1– 2 mm in the drawing represents 1 mm in real life

• Actual size representation– 1:1– Object is life size

Scale

• What scale would you use to draw a …– Train– Spider– A parc statue– A pencil

5. Cross-Sections and Sections

Cross-sections vs Section

• Cross-Sections:– Shows the interior details of an object as if it

were cut by a cutting plane

• Sections:– Shows the interior details of a part of an

object as if it were but by a cutting plane

Cross-Section

Sections

• Revolved Section • Removed Section

6. Links and Guides

Guides

• Rotational

• Helical

• Translational

Links

Direct Indirect

Removable Non-removable

Partial Complete

Flexible Rigid

7. Properties

Properties

• Malleable

• Ductile

• Hardness

• Elasticity

• Resilience

• Stiffness

Materials

• Ceramic

• Wood

• Modified wood

• Metal