CELLS MAKE UP THE HUMAN BODY

Question 1

Cells

Answer 1

Cell’s are the smallest structure that can perform life’s functions

Question 2

Cell theory

Answer 2

All living organisms are made up of cells, cells are the fundamental units of life and cells arise from pre-existing cells

Question 3

6 main parts that the cell is made up from.

Answer 3

1. cell membrane - outer border of the cell.
2. cytoplasm - jelly- like fluid that has organelles suspended in it.
3. cytosol - the liquid part of the cytoplasm
4. cytoskeleton - internal scaffolding of proteins fibres in the cytoplasm
5. organelles - structures that are suspended in the cytoplasm that are used to carry out specific functions
6. inclusions - chemicals inside of the cells including granules and liquid droplets in the cell

Question 4

Cell membrane

Answer 4

Border of the cell that separates the intracellular fluid from the extracellular fluid.

Question 5

Cytoplasm

Answer 5

A jelly like watery material that is located in side the cell, it covers all material except the nucleus and is made up of cytosol and organelles

Question 6

Cytosol

Answer 6

the liquid part of the cytoplasm, made from 75% - 90% of water, with a complex mixture of dissolved substances such as carbohydrates and salts.

Most metabolic reactions occur here. Also plays a role of controlling the osmotic pressure of the cell and the flow of chemicals in and out of the cell.

Question 7

Nucleus

Answer 7

• Structure/ organelles of a cell that contains chromosomes and DNA

Question 8

A nuclear membrane

Answer 8

A membrane that separates the nucleus from the cytoplasm. It is also known to be a double membrane

Question 9

Nuclear pores

Answer 9

Structure that allows large molecules, such as RNA to enter and leave the nucleus.

Question 10

DNA

Answer 10

• Deoxyribonucleic-acid, contains inherited information

Question 11

Nucleolus

Answer 11

Located inside of the nucleus, plays apart in manufacturing proteins.

Question 12

Ribosomes

Answer 12

Spherical organelles, that make proteins via the amino acids joining together.

Can be found free in the cytoplasm of attached to the endoplasmic reticulum.

Question 13

Endoplasmic reticulum

Answer 13

Pais or parallel membrane that extend through the cytoplasm from the cell membranes to the nuclear membrane.

• membranes of the ER help provide a surface for chemical reactions and
• channels help store or transport molecules.

Smooth, when no ribosomes are attached

rough, when ribosomes are attached

Question 14

Golgi body

Answer 14

• A series of flattened membrane that are stacked upon each other.
• They are positions near the nucleus.
• Their function is to modify proteins and package into vesicles for the secretion of the cell.
• The proteins come from the ribosomes via the channels of the ER

Question 15

Lysosomes

Answer 15

• Are small spheres, bounded by a membrane that are formed from the Golgi-body.
• They contain digestive enzymes that are able to break down substances such as material inside of a vesicle or worn-out organelles.

Question 16

Mitochondria

Answer 16

• A spherical structure that spread across the cytoplasm.
• this organelle consists of a double membrane.
• responsible for generating energy for the cells activities through the use of cellular respiration.

Question 17

Vesicle

Answer 17

small bound sac of membrane that transports stuff like proteins and wastes.

Question 18

Cilia and flagella

Answer 18

Cilia- short and numerous hair like projections that move the whole cell or substances over the surfaces of cells.

Flagella- long, only 1 or 2 projections, located on sperm.

Question 19

Cytoskeleton

Answer 19

A framework of protein fibres that gives the cell its shape and assists it for movements.

Includes:

Microtubules- Hollow rods that keep organelles in place or help them move around the cell.

Microfilaments - Move materials around the cytoplasm or move the whole cell.

Question 20

Inclusions

Answer 20

Chemical substances that are not apart of the cells but are found in the cytoplasm of the cell.
(HAEMOGLOBIN)

Question 21

Extracellular fluid

Answer 21

Fluid that surrounds the cell, it provides the cell with nutrients it needs and removes wastes it produces

Question 22

Homeostasis

Answer 22

Body systems work together to keep the cellular environment constant.

Question 23

Fluid Mosaic Model

Answer 23

Current model that describes the cell membrane.

Fluid - Molecules are constantly changing position in the cell membrane

Mosaic - The cell membrane is composed of many different kinds of molecules.

Question 24

Structure of the cell membrane

Answer 24

• consists of a phospholipid bilayer, where the hydrophilic heads are facing out and hydrophobic tails are facing in.
• They drift from place to place keeping the membrane fluid
• Embedded in the phospholipid bilayer are proteins molecules and cholestorol.
• some examples of protein molecules are:
• carrier proteins
• channel proteins
• cell identity markers

which help for the transports of material in and out of cells.

Question 25

Functions of the cell membrane.

Answer 25

1. acts like a barrier - separates the extracellular fluid from the intracellular fluid, as they have very different compositions. 2. It regulates passages of materials - Controls movements of materials into and out of the cell. 3. It is sensitive to changes - First part of the cell to be affected by changes from the extracellular fluid. 4. It helps support the cell - Inner layer is attached to microfilaments that give support to the cell.

Question 26

Cell membrane permeablility

Answer 26

The cell membranes is known to be (differentially/ semi/ selectively) permeable. This results it to allow certain ions and molecules to pass through but restrict the movement of others.

Question 27

Ways material can pass through the cell (2 ways)

Answer 27

1. active - with the use of energy in the form of adenosine triphosphate (ATP). 2. passive - Do not use energy

Question 28

Transports across the cell membrane.

Answer 28

- Simple diffusion 1. simple diffusion of solute (passive) 2. Osmosis (passive) - Facilitated transport 1. facilitated diffusion (passive) 2. Active transport (active) - Vesicular transport 1. Endocytosis (Active) 2. Exocytosis (Active)

Question 29

Simple diffusion

Answer 29

A passive transport technique, where molecules move from an area of high concentration to an area of low concentration. Molecules move along the concentration gradient. Substances: Co2, alcohol, fatty acids, steroids, ions and soluble drugs

Question 30

Osmosis

Answer 30

A passive transport technique where water molecules are moved from an area of high concentration to an area of low concentration along the concentration gradient. substances include: water

Question 31

Facilitate diffusion

Answer 31

A passive transport technique that moves water-soluble molecules from an area of high concentration to an area of low concentration, along the concentration gradient via the use of channel proteins. Substance include: Glucose and amino acids.

Question 32

Active transport

Answer 32

An active transport methods that moves larger substances across the cell membrane from an area of low concentration to an area of high concentration, against the concentration gradient. Via the help of carrier proteins. Substance include: certain ions, glucose and amino acids

Question 33

Endocytosis

Answer 33

An active transport methods that moves molecules across the cell membrane into the cell by packaging large material into vesicles. Energy is needed to form vesicles. Pinocytosis - vesicles contain liquid particels Phagocytosis - vesicles contain solid particles. Substances : Cholesterol, ions

Question 34

Exocytosis

Answer 34

An active transport methods that moves molecules across the cell membrane out of the cell by packaging large material into vesicles. Energy is needed to form vesicles. Substances : secretions

Question 35

How cells make up to body

Answer 35

CELLS > TISSUES > ORGANS > SYSTEMS.

Question 36

Tissues

Answer 36

A group of cells that are in similar structure work together to carry out specific functions

Question 37

Types of tissues

Answer 37

1. Epithelial 2. Connective 3. Muscular - Smooth - Skeletal - Cardiac 4. Nervous

Question 38

Epithelial

Answer 38

- Covering or a lining tissue. - The skin, heart, stomach and liver and covered with epithelium. - Cells are very closely joined together to form a smooth surface. Single layer - single multilayer - stratified flat - squamous square - cuboidal tall and skinny - columnar

Question 39

Connective

Answer 39

- Supports body and helps hold body parts together. - not closely held together. - separated by a non-cellular material called a matrix. includes: bones, blood, cartilage, tendons.

Question 40

Muscular

Answer 40

Also known as muscle fibres, they are long, thin and are able to contract to become shorted. Skeletal muscle - Makes up muscle attached to bones. - We have voluntary control - striated Smooth muscle - found in walls of the stomach and intestine. - not striated - involuntary Cardiac muscle - Makes up most of the heart - involuntary - striated

Question 41

Nervous Tissue

Answer 41

- Made up of specialised nerve cells called Neurons. - They have long projections from the body of the cells. - Messages can be carried along these projections when neurons are stimulated.

Question 42

Organs

Answer 42

Body structures that are made up of two or more tissues, which work together to carry out a particular task

Question 43

Systems

Answer 43

Group of organs that work together to carry out a particular task.